CN113868931B - Composite material finite element modeling method, system and storage medium - Google Patents

Abstract

The invention relates to the technical field of computer aided engineering, and discloses a composite material finite element modeling method, system and storage medium. The composite material finite element modeling method includes: generating a reinforcement phase geometric model and an overall domain geometric model corresponding to the composite material; assembling the reinforcement phase geometric model into the overall domain geometric model to obtain a composite material geometric model; The finite element mesh division of the reinforcement phase geometric model and the overall domain geometry model is carried out to obtain the initial composite material finite element model; the spatial coincidence area of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model is sequentially carried out. The nodal degrees of freedom are coupled to obtain a composite finite element model. On the premise of ensuring the accuracy of finite element modeling, the invention reduces the calculation cost and saves the modeling time cost.

Description

Composite finite element modeling method, system and storage medium

technical field

The invention relates to the technical field of computer-aided engineering, in particular to a composite material finite element modeling method, system and storage medium.

Background technique

A composite material is a material composed of reinforcing phases and matrices with different properties. Through the complementarity and correlation of the properties of each component, comprehensive properties that cannot be achieved by a single component material can be obtained. Since the properties of composite materials are closely related to the shape, content, distribution and other factors of their constituent materials, the macroscopic properties of the materials can be improved by adjusting the microscopic configuration of the constituent materials.

Finite element simulation is an important analysis method to explore the influence of micro-configuration changes on the macro-performance of materials. For composite materials with complex spatial configurations, finite element modeling is the focus of simulation. Due to the complexity of the enhanced phase space configuration, the complementary matrix region will have geometric features such as sharp corners and thin walls. At the same time, it is necessary to share nodes between the reinforcement phase and the matrix to ensure the coordination of the deformation of the two-phase materials at the interface, which not only brings difficulties to the division of high-quality finite element meshes, but also causes the finite element model due to the small size of local elements. The overall number of units is huge, which greatly increases the time cost of simulation calculation.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a composite material finite element modeling method, system and storage medium, aiming at solving the technical problem of how to reduce the time cost of simulation calculation under the premise of ensuring the accuracy of composite material finite element modeling.

A first aspect of the present invention provides a composite material finite element modeling method, comprising:

The reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material are generated respectively;

Based on the spatial position of the reinforcing phase in the composite material, correspondingly assembling the reinforcing phase geometric model into the overall domain geometric model to obtain a composite material geometric model;

Perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometry model in the composite material geometric model respectively, and obtain an initial composite material with the characteristics of reinforcement phase mesh element and overall domain mesh element division. metamodel;

The coupling processing of nodal degrees of freedom is sequentially performed on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model to obtain a composite material finite element model.

Optionally, in a first implementation manner of the first aspect of the present invention, performing finite element mesh division on the reinforcement phase geometric model and the overall domain geometric model in the composite material geometric model, respectively, The initial composite finite element model with the characteristics of the reinforcement phase mesh element and the overall domain mesh element is obtained, including:

respectively setting a first mesh element size for dividing the augmented phase geometric model and a second mesh element size of the overall domain geometric model;

According to the first mesh element size, the reinforcement phase geometric model is subjected to finite element mesh division, and according to the second mesh element size, the overall domain geometric model is subjected to finite element mesh division to obtain Initial composite finite element model with enhanced phase mesh elements and integral domain mesh elements.

Optionally, in the second implementation manner of the first aspect of the present invention, the nodal degrees of freedom are sequentially performed on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite finite element model. Coupling processing, the obtained composite material finite element model includes:

searching for all spatially coincident regions where the overall domain grid cell includes the enhancement phase grid cell;

The node constraint relationship between the reinforcement phase mesh element and the overall domain mesh element in each of the spatial coincidence regions is respectively set to complete the coupling of the nodal degrees of freedom to obtain a composite material finite element model.

Optionally, in a third implementation manner of the first aspect of the present invention, each of the overall domain grid units includes a plurality of overall domain grid nodes, and each of the enhancement phase grid units includes a plurality of enhancement phase grid units. the phase grid node, the searching for a spatially coincident region where the overall domain grid unit includes the enhanced phase grid unit includes:

Step S11, traverse all the overall domain grid units, number the overall domain grid nodes where each overall domain grid unit is in the same position, obtain the unit number of each overall domain grid unit, and assign the numbered overall domain grid nodes The coordinates of the first node are stored in association with the unit number;

Step S12, select any enhancement phase grid node, obtain the second node coordinates of the enhancement phase grid node, and perform a rounding algorithm on the second node coordinates to obtain the comparison coordinates;

Step S13: Calculate the two-norm of the comparison coordinates and the first node coordinates of the overall domain grid nodes of each number respectively, obtain the first node coordinates corresponding to the minimum two-norm, and read the corresponding first node coordinates. The unit number, the overall domain grid unit corresponding to the unit number is the spatial coincidence area containing the enhancement phase grid unit;

Step S14, traverse the remaining enhancement phase grid nodes in sequence and repeat steps S12-S13 until there are no untraversed enhancement phase grid nodes.

Optionally, in a fourth implementation manner of the first aspect of the present invention, each of the overall domain grid units includes a plurality of overall domain grid nodes, and each of the enhancement phase grid units includes a plurality of enhancement phase grid units. Phase grid nodes, the node constraint relationship between the enhanced phase grid element and the overall domain grid element in each of the spatial coincidence regions is respectively set, and the coupling of the nodal degrees of freedom is completed, and the obtained composite material finite element model includes:

Step S21, selecting the first node coordinates corresponding to each overall domain grid node and the second node coordinates corresponding to each enhancement phase grid node in any spatial coincidence region;

Step S22: Substitute a selected second node coordinate and all first node coordinates into a preset interpolation function in turn, and build a node constraint relationship based on the interpolation function, and complete the enhanced phase grid node in the selected spatial overlap region and the whole. Nodal degrees of freedom coupling between domain mesh nodes;

Step S23 , traverse the remaining spatial coincidence regions in sequence and repeat steps S21 - S22 until there is no untraversed spatial coincidence region, and obtain a composite material finite element model.

Optionally, in a fifth implementation manner of the first aspect of the present invention, the separately generating the reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material includes:

Based on the modeling method of the reinforcing phase in the composite material, the geometric model of the reinforcing phase is generated;

Based on the morphological characteristics and distribution parameters of the reinforcement phase in the composite material, a global domain geometry model is generated.

Optionally, in a sixth implementation manner of the first aspect of the present invention, the generation of the reinforcement phase geometric model based on the modeling manner of the reinforcement phase in the composite material further includes:

If the modeling method of the reinforcement phase is to model the geometric model according to the extracted microstructure and morphology of the real composite material, the matrix geometric model in the real composite material geometric model is eliminated to obtain the reinforcement phase geometric model;

If the modeling method of the enhancement phase is to perform modeling according to the statistical data of the distribution parameters of the enhancement phase, when the enhancement phase is a particle body, a Thiessen polygon is constructed according to the distribution parameters of the enhancement phase, and the particle distribution is generated based on the Thiessen polygon. model, and the particle distribution model is used as the reinforcement phase geometric model; when the reinforcement phase is a continuous fiber bundle, a fiber weaving model is generated according to the distribution parameters of the reinforcement phase, and the fiber weaving model is used as the reinforcement phase geometric model.

Optionally, in a seventh implementation manner of the first aspect of the present invention, the generation of the reinforcement phase geometric model based on the modeling manner of the reinforcement phase in the composite material further includes:

Based on the morphological characteristics of the reinforcement phase in the composite material, the geometric shape of the overall domain geometric model is determined, and based on the distribution parameters of the reinforcement phase in the composite material, the size of the overall domain geometric model is determined;

According to the determined geometric shape and size of the overall domain geometric model, the overall domain geometric model is generated.

A second aspect of the present invention provides a composite material finite element modeling system, comprising:

The model generation module is used to respectively generate the reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material;

a model assembling module, configured to assemble the geometric model of the reinforcing phase into the overall domain geometric model correspondingly based on the spatial position of the reinforcing phase in the composite material, to obtain a geometric model of the composite material;

A meshing module is used to perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometry model in the composite material geometric model respectively, to obtain a mesh element with reinforcement phase and an overall domain mesh element The initial composite finite element model of the partitioned features;

The nodal coupling module is used to sequentially perform nodal degree of freedom coupling processing on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model to obtain the composite material finite element model.

Optionally, in the first implementation manner of the second aspect of the present invention, the meshing module is specifically configured to:

a size setting unit, configured to respectively set the size of the first mesh element used to divide the reinforcement phase geometric model and the second mesh element size of the overall domain geometric model;

a meshing unit for performing finite element meshing on the reinforcement phase geometric model according to the first mesh element size, and performing finite element meshing on the overall domain geometric model according to the second mesh element size The finite element mesh is divided to obtain the initial composite finite element model with the characteristics of the reinforcement phase mesh element and the overall domain mesh element division.

Optionally, in a second implementation manner of the second aspect of the present invention, the node coupling module includes:

a coincidence area search unit, configured to search for a spatial coincidence area where the overall domain grid unit includes the enhancement phase grid unit;

The nodal coupling unit is used to set the nodal constraint relationship between the enhanced phase grid unit and the overall domain grid unit in the spatial coincidence region, and perform nodal degree of freedom coupling processing based on the nodal constraint relationship to obtain a composite material finite element model.

Optionally, in a third implementation manner of the second aspect of the present invention, each of the overall domain grid units includes a plurality of overall domain grid nodes, and each of the enhancement phase grid units includes a plurality of enhancement phase grid units. Phase grid nodes, the coincidence area search unit includes:

The numbering subunit is used to traverse all the overall domain grid units, number the overall domain grid nodes where each overall domain grid unit is in the same position, obtain the unit number of each overall domain grid unit, and assign the numbered overall domain grid unit The first node coordinates of the grid nodes are stored in association with the unit number;

The rounding subunit is used to select any enhancement phase grid node, obtain the second node coordinates of the enhancement phase grid node, and perform a rounding algorithm on the second node coordinates to obtain the comparison coordinates;

The confirmation subunit is used to calculate the two-norm of the comparison coordinates and the first node coordinates of the overall domain grid nodes of each number respectively, obtain the first node coordinates corresponding to the minimum two-norm, and read the first node The unit number corresponding to the coordinate, the overall domain grid unit corresponding to the unit number is the spatial coincidence area containing the enhancement phase grid unit;

The first traversal subunit is used for traversing the remaining enhancement phase grid nodes in sequence and repeatedly executing the rounding subunit and the confirmation subunit until there are no untraversed enhancement phase grid nodes.

Optionally, in a fourth implementation manner of the second aspect of the present invention, each of the overall domain grid units includes a plurality of overall domain grid nodes, and each of the enhancement phase grid units includes a plurality of enhancement phase grid units. Phase grid nodes, the node coupling unit includes:

Selecting subunits for selecting the first node coordinates corresponding to each overall domain grid node and the second node coordinates corresponding to each enhancement phase grid node in any spatial coincidence region;

Substitute into a subunit, for sequentially substituting the selected one second node coordinate and all first node coordinates into the preset interpolation function, and based on the interpolation function, construct the node constraint relationship, and complete the enhanced phase grid in the selected spatial coincidence area Nodal degrees of freedom coupling between nodes and global domain mesh nodes;

The second traversing subunit is used for traversing the remaining spatial coincidence regions in sequence and repeating the selection subunit and the substitution subunit until there is no untraversed spatial coincidence region to obtain a composite material finite element model.

Optionally, in a fifth implementation manner of the second aspect of the present invention, the model generation module includes:

The reinforcement phase model element is used to generate the reinforcement phase geometric model based on the modeling method of the reinforcement phase in the composite material;

The global domain model element is used to generate the global domain geometric model based on the morphological characteristics and distribution parameters of the reinforcement phase in the composite material.

Optionally, in the sixth implementation manner of the second aspect of the present invention, the enhanced phase model unit may also be specifically used for:

If the modeling method of the reinforcement phase is to model the geometric model according to the extracted microstructure and morphology of the real composite material, the matrix geometric model in the real composite material geometric model is eliminated to obtain the reinforcement phase geometric model;

If the modeling method of the enhancement phase is to perform modeling according to the statistical data of the distribution parameters of the enhancement phase, when the enhancement phase is a particle body, a Thiessen polygon is constructed according to the distribution parameters of the enhancement phase, and the particle distribution is generated based on the Thiessen polygon. model, and the particle distribution model is used as the reinforcement phase geometric model; when the reinforcement phase is a continuous fiber bundle, a fiber weaving model is generated according to the distribution parameters of the reinforcement phase, and the fiber weaving model is used as the reinforcement phase geometric model.

Optionally, in the seventh implementation manner of the second aspect of the present invention, the overall domain model unit may also be used for:

Based on the morphological characteristics of the reinforcement phase in the composite material, the geometric shape of the overall domain geometric model is determined, and based on the distribution parameters of the reinforcement phase in the composite material, the size of the overall domain geometric model is determined;

According to the determined geometric shape and size of the overall domain geometric model, the overall domain geometric model is generated.

A third aspect of the present invention also provides a computer-readable storage medium, where instructions are stored on the computer-readable storage medium, and when the instructions are executed by a processor, the finite element modeling of composite materials according to the first aspect is implemented method.

In the technical solution provided by the present invention, when constructing the geometric model of the composite material, the overall domain is used instead of the matrix for modeling, and the reinforcement phase geometric model and the overall domain geometric model are respectively generated, and then the two geometric models are assembled to obtain a composite Material geometry model; then separately perform finite element meshing on the reinforcement phase part and the overall domain part of the composite material geometry model to obtain corresponding multiple reinforcement phase mesh elements and overall domain mesh elements, and then sequentially mesh the reinforcement phase mesh. The spatial coincidence area of the element and the overall domain mesh element is subjected to coupling processing of nodal degrees of freedom to obtain the final composite finite element model. The invention introduces the concept of the overall domain, and through the finite element mesh division of the overall domain, various meshing problems caused by the direct finite element meshing of the matrix with complex spatial configuration are avoided, and at the same time the enhancement is achieved. The independent mesh division of the phase geometry model and the overall domain geometry model reduces the correlation between the mesh divisions of the two, making the finite element modeling accuracy controllable, and realizing the premise of ensuring the accuracy of the finite element modeling of composite materials. Reduce the time cost of simulation calculation.

Description of drawings

1 is a schematic diagram of a first embodiment of a finite element modeling method for composite materials in an embodiment of the present invention;

2 is a schematic diagram of a particle-reinforced phase geometric model of a finite element modeling method for composite materials in an embodiment of the present invention;

FIG. 3 is a schematic diagram of a fiber-reinforced phase geometric model of a composite material finite element modeling method in an embodiment of the present invention;

4 is a schematic diagram of a second embodiment of the finite element modeling method for composite materials in the embodiment of the present invention;

5 is a schematic diagram of a part of the enhancement phase grid unit, the overall domain grid unit and the spatial overlap area in an embodiment of the present invention;

FIG. 6 is a schematic diagram of the spatial relationship between an integral domain grid element node and a reinforcement phase grid node in a finite element modeling method for composite materials according to an embodiment of the present invention;

7 is a schematic diagram of a third embodiment of the finite element modeling method for composite materials in the embodiment of the present invention;

Fig. 8 is the initial composite material finite element model of the particle-reinforced phase composite material of the composite material finite element modeling method in the embodiment of the present invention;

FIG. 9 is a schematic diagram of the fourth embodiment of the finite element modeling method of composite materials in the embodiment of the present invention;

FIG. 10 is a schematic diagram of distribution parameters of the fiber-reinforced phase geometric model of the composite material finite element modeling method in the embodiment of the present invention;

11 is the real microstructure and morphology of the particle-reinforced phase composite material by the finite element modeling method of the composite material in the embodiment of the present invention;

Fig. 12 is the initial composite material finite element model of the fiber reinforced composite material of the composite material finite element modeling method in the embodiment of the present invention;

13 is a schematic diagram of an embodiment of a composite material finite element modeling system in an embodiment of the present invention;

FIG. 14 is a schematic diagram of another embodiment of the composite material finite element modeling system in the embodiment of the present invention.

Detailed ways

Embodiments of the present invention provide a composite material finite element modeling method, system, and storage medium. The present invention introduces the concept of an overall domain, and through the finite element mesh division of the overall domain, it is avoided to directly create a matrix with a complex spatial configuration. Various meshing problems caused by finite element meshing, and at the same time, the independent meshing of the enhanced phase geometry model and the overall domain geometry model is realized, which reduces the correlation between the two meshes, and makes the finite element model. The mold accuracy is controllable, which reduces the time cost of simulation calculation on the premise of ensuring the accuracy of the finite element modeling of composite materials.

The terms "first", "second", "third", "fourth", etc. (if present) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed steps or units, but may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

For ease of understanding, the following describes the specific process of the embodiment of the present invention, referring to FIG. 1 , the first embodiment of the finite element modeling method for composite materials in the embodiment of the present invention includes:

101. Generate the reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material respectively;

In this embodiment, the composite material refers to a material composed of a reinforcing phase with different properties and a matrix. The structure of the composite material is usually that the matrix is the continuous phase; and the other phase is an independent form distributed throughout the continuous phase. in the dispersed phase. Compared with the continuous phase, this disperse phase has superior properties and can significantly enhance the properties of the material, so it is often called the reinforcement phase. In most cases, the reinforcement is harder than the matrix, and the strength and stiffness are greater than the matrix. The reinforcing phase can be fibers and their braids, or granular or dispersed fillers. According to the morphology of the reinforcement phase, composite materials can be divided into particle, short fiber and continuous fiber reinforced composite materials.

In this embodiment, the geometric model is a model that describes the shape and size of an object by using regular or irregular geometry, including but not limited to two-dimensional geometric models, three-dimensional geometric models, geometric models with regular shapes, and geometric models with irregular shapes . The reinforcement phase geometric model is a geometric model with reinforcement phase geometric features, including but not limited to particle reinforcement phase geometry model, short fiber reinforcement phase geometry model, fiber bundle reinforcement phase geometry model, as shown in Figure 2 is the particle reinforcement phase geometry model, Figure 3 is a geometric model of the fiber bundle reinforcement phase. Among them, the short fiber reinforced phase can be used to build the geometric model of the reinforced phase in the same way as the particle reinforced phase.

In this embodiment, the overall domain includes, but is not limited to, geometric bodies with regular shapes, cubes, regular hexahedrons, and matrix regions for removing defects including but not limited to voids and thin walls. The global domain geometry is preferably a regular geometry capable of having the largest area of overlap with the augmentation phase geometry and having the smallest volume. The material properties of the matrix can be assigned to the overall domain to achieve the effect of simulation.

In this embodiment, the method of generating the geometric model is not limited, including but not limited to using a SEM scanning electron microscope to extract the real microstructure of a composite material sample to generate a geometric model, and generating a geometric model according to the collected statistical data of a plurality of composite material samples .

102. Based on the spatial position of the reinforcement phase in the composite material, correspondingly assemble the reinforcement phase geometric model into the overall domain geometric model to obtain a composite material geometric model;

In this embodiment, the spatial position specifically refers to the spatial position distribution of the reinforcement phase in the matrix, and the spatial position may be obtained based on scanning a real composite material with an electron microscope, or may be generated by using a random generation algorithm.

In this embodiment, after obtaining the spatial position distribution of the reinforcement phase in the matrix, the geometric model of the reinforcement phase can be assembled into the overall domain geometric model with reference to the spatial position. Specifically, the reinforcement phase geometric model is used to replace the overall domain geometric model. In the part of the geometric model in the same spatial position, the geometric model of the composite material obtained by the assembly does not directly use the geometric model of the matrix phase, which facilitates the finite element mesh division of the geometric model of the enhanced phase and the geometric model of the overall domain, and avoids the need for direct analysis of the matrix phase. To solve the problems of element distortion and too small element size caused by mesh division, parametric finite element modeling is realized.

In this embodiment, the composite material geometric model includes but is not limited to being obtained by assembling one or more reinforcement phase geometric models into the overall domain geometric model.

103. Perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometric model in the composite material geometric model, respectively, to obtain an initial composite with the division characteristics of reinforcement phase mesh elements and overall domain mesh elements Material finite element model;

In this embodiment, the finite element refers to a finite number of elements (Finite Element), and the basic solution idea is to divide the computational domain into a finite number of non-overlapping elements. The division method includes, but is not limited to, grid division, dividing the overall domain into a finite number of non-overlapping grid cells.

In this embodiment, the finite element mesh division method includes, but is not limited to, using tetrahedral elements and regular hexahedral elements to divide the reinforcement phase geometric model and the overall domain geometric model into mesh elements respectively. The composite material finite element model obtained after division is The reinforcement phase mesh element is composed of the integral domain mesh element.

In this embodiment, the reinforcement phase mesh element refers to the mesh element obtained after the reinforcement phase geometric model is divided into meshes, including but not limited to the tetrahedral reinforcement phase mesh element; the overall domain mesh element refers to the reinforcement phase geometric model. After meshing, the obtained mesh elements include but are not limited to regular hexahedral overall domain mesh elements.

In this embodiment, after the initial composite material finite element model is divided into mesh elements, it is necessary to further perform node coupling association between the reinforcement phase mesh element and the overall domain mesh element, so as to achieve complete equivalence of the mechanical properties of the material.

104. Perform coupling processing of nodal degrees of freedom on the spatial overlap region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model in turn, to obtain a composite material finite element model.

In this embodiment, the spatially overlapping area refers to an area including an enhancement phase grid unit and an overall domain grid unit, including but not limited to a part of the enhancement phase grid unit, one enhancement phase grid unit, or multiple enhancement phase grid units and one enhancement phase grid unit Coincidence regions of the overall domain grid cells.

In this embodiment, the degree of freedom of a point in the three-dimensional space is 3, and the point can have three degrees of freedom, which are equivalent to the three degrees of freedom of the horizontal axis, the vertical axis, and the vertical axis in the three-dimensional space coordinate system. The nodal degree of freedom coupling includes, but is not limited to, the nodal degree of freedom coupling of the enhanced phase node and the integral domain element node. When generating a finite element model, it is necessary to describe the relationship of each degree of freedom between the nodes of the enhanced phase and the integral domain element, so that the nodes of each enhanced phase and the integral domain element can be displaced cooperatively in the process of material deformation.

In one embodiment, after the coupling processing of nodal degrees of freedom is performed on the initial composite material finite element model, the stiffness property of the material of the reinforcing phase is further modified to achieve equivalent mechanical properties of the material.

In this embodiment, when constructing the geometric model of the composite material, the overall domain is used instead of the matrix for modeling, and the reinforcement phase geometric model and the overall domain geometric model are respectively generated, and then the two geometric models are assembled to obtain the composite material geometric model. ; Then separately perform finite element meshing on the reinforcement phase part and the overall domain part of the composite material geometric model, and obtain a plurality of corresponding reinforcement phase mesh elements and overall domain mesh elements, and then sequentially analyze the reinforcement phase mesh elements and the overall domain mesh elements. The spatial coincidence area of the domain mesh element is subjected to nodal degree of freedom coupling processing, and the final composite finite element model is obtained. The invention introduces the concept of the overall domain, and through the finite element mesh division of the overall domain, various meshing problems caused by the direct finite element meshing of the matrix with complex spatial configuration are avoided, and at the same time the enhancement is achieved. The independent mesh division of the phase geometry model and the overall domain geometry model reduces the correlation between the mesh divisions of the two, making the finite element modeling accuracy controllable, and realizing the premise of ensuring the accuracy of the finite element modeling of composite materials. Reduce the time cost of simulation calculation.

Referring to FIG. 4, the second embodiment of the composite material finite element modeling method in the embodiment of the present invention includes:

201. Generate a reinforcement phase geometric model and an overall domain geometric model corresponding to the composite material respectively;

202. Based on the spatial position of the reinforcement phase in the composite material, correspondingly assemble the reinforcement phase geometric model into the overall domain geometric model to obtain a composite material geometric model;

203. Perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometry model in the composite material geometric model, respectively, to obtain an initial composite with the division characteristics of reinforcement phase mesh elements and overall domain mesh elements Material finite element model;

204. Search for all spatial coincidence regions where the overall domain grid unit includes the enhancement phase grid unit;

In this embodiment, for ease of understanding, a partial cross-section of the initial composite finite element model is shown in Figure 5, where 1 is a part of the overall domain mesh element; 2 is a plurality of enhanced phase meshes included in the part of the overall domain mesh element grid cell; 3 shows the enhanced phase grid node; 4 is the spatial coincidence area. Spatial coincidence refers to the overlapping part of the space occupied by the overall domain geometry model and the space occupied by the augmentation phase geometry model. The spatially coincident area refers to the area that contains the reinforcement phase grid unit and the overall domain grid unit, including but not limited to part of the reinforcement phase grid unit, one reinforcement phase grid unit, or multiple reinforcement phase grid cells and an overall domain grid unit the overlapping area.

Optionally, in an embodiment, each of the overall domain grid units includes a plurality of overall domain grid nodes, and each of the enhancement phase grid units includes a plurality of enhancement phase grid nodes, the above step 204 The search algorithm for the coincident region in the preset space further includes:

Step S11, traverse all the overall domain grid units, number the overall domain grid nodes where each overall domain grid unit is in the same position, obtain the unit number of each overall domain grid unit, and assign the numbered overall domain grid nodes The coordinates of the first node are stored in association with the unit number;

Step S12, select any enhancement phase grid node, obtain the second node coordinates of the enhancement phase grid node, and perform a rounding algorithm on the second node coordinates to obtain the comparison coordinates;

Step S13: Calculate the two-norm of the comparison coordinates and the first node coordinates of the overall domain grid nodes of each number respectively, obtain the first node coordinates corresponding to the minimum two-norm, and read the corresponding first node coordinates. The unit number, the overall domain grid unit corresponding to the unit number is the spatial coincidence area containing the enhancement phase grid unit;

Step S14, traverse the remaining enhancement phase grid nodes in sequence and repeat steps S12-S13 until there are no untraversed enhancement phase grid nodes.

In this optional embodiment, as shown in FIG. 5 , each overall domain grid unit includes a plurality of overall domain grid nodes, and each enhancement phase grid unit includes a plurality of enhancement phase grid nodes. Nodes are points selected for identification after grid division, including but not limited to all intersections where grid lines intersect. The number of enhancement phase nodes in the spatially overlapping region is not limited, including but not limited to one or more enhancement phase nodes.

In this optional embodiment, a sorting function is used to sort multiple nodes of the overall domain grid unit, as shown in FIG. 6 , A is the overall domain grid unit, B is the enhancement phase grid node, preferably the overall domain grid The eight nodes (①node-⑧node) of the element are sorted. The method for selecting the same position includes, but is not limited to, selecting the node with the smallest sum of coordinate values in the sequence. For example, the node ① in the overall domain grid unit in Fig. 6 and the nodes at the same position of the other overall domain grid units are selected for numbering, and the unit number of the overall domain grid unit is obtained.

In this optional embodiment, the unit number refers to the number of the grid unit of the overall domain, and the numbering method is not limited.

In this optional embodiment, the coordinates of the first node refer to the coordinates of any node among the multiple nodes of the grid unit in the overall domain. Wherein, the first node coordinate of the number is the coordinate of the node at the same position in the selected sequence.

In this optional embodiment, traversing refers to sequentially accessing grid cells in the overall domain grid in a certain order, and selecting grid nodes at the same position of each grid cell for numbering.

In this optional embodiment, after the associated storage, the corresponding overall domain grid unit can be found according to the coordinates of the numbered first node, and the association method is not limited.

In this optional embodiment, the second node coordinate refers to the coordinate of any node of the enhanced phase grid unit, and the comparison coordinate refers to the coordinate obtained after rounding up the calculation, which is used as the comparison value in the search process, because the comparison coordinate is approximately equal to The first node coordinate of the number of the overall domain grid cell corresponding to the enhancement phase node.

In this optional embodiment, a rounding algorithm is used to calculate the comparison coordinates, and the formula of the rounding algorithm is as follows:

是整体域网格单元沿横轴的网格单元尺寸，

是整体域网格单元沿纵轴的网格单元尺寸，

是整体域网格沿竖轴的网格单元尺寸，

表示增强相网格单元节点的坐标，

表示比较坐标，k，p，q为常数。in

is the grid cell size along the horizontal axis of the overall domain grid cells,

is the grid cell size along the vertical axis of the global domain grid cells,

is the grid cell size along the vertical axis of the overall domain grid,

represent the coordinates of the enhancement phase mesh element nodes,

Indicates the comparison coordinates, k, p, q are constants.

In this optional embodiment, the comparison method is not limited, including but not limited to using a two-norm method for comparison. The first node coordinates, the second node coordinates, and the comparison coordinates have errors in data storage, so it is more accurate to use the two-norm formula for confirmation and comparison. The two-norm refers to the two-norm of the comparison coordinate and the numbered first node coordinate, which is equivalent to calculating the straight-line distance between the comparison coordinate and the numbered first node coordinate of each unit. When the absolute value of the two-norm is the smallest, the first node coordinate closest to the comparison coordinate is obtained.

In this optional embodiment, traversing the remaining enhancement phase grid nodes in sequence includes, but is not limited to, sequentially traversing all nodes in the current spatial coincidence area except the traversed enhancement phase grid nodes, and traversing other spatial coincidence areas that have not been traversed. The enhanced phase mesh nodes are traversed. The condition for the end of the traversal loop is that all enhancement phase grid nodes have completed the traversal operation.

205. Set the node constraint relationship between the reinforcement phase mesh element and the overall domain mesh element in each of the spatial coincidence regions respectively, complete the coupling of the nodal degrees of freedom, and obtain a composite material finite element model.

In this embodiment, the node constraint relationship refers to using a series of constraint conditions to construct the relationship between the enhanced phase element and the overall domain element, and the enhanced phase element and the overall domain element can be combined to change, approaching the actual change of the material. The nodal degree of freedom coupling is to use the nodal constraint relationship to complete the coupling processing of two or more objects under the spatial degree of freedom.

Optionally, in an embodiment, each of the overall domain grid units includes a plurality of overall domain grid nodes, and each of the enhancement phase grid units includes a plurality of enhancement phase grid nodes. The above step 205 Also includes:

Step S21, selecting the first node coordinates corresponding to each overall domain grid node and the second node coordinates corresponding to each enhancement phase grid node in any spatial coincidence region;

Step S22: Substitute a selected second node coordinate and all first node coordinates into a preset interpolation function in turn, and build a node constraint relationship based on the interpolation function, and complete the enhanced phase grid node in the selected spatial overlap region and the whole. Nodal degrees of freedom coupling between domain mesh nodes;

Step S23 , traverse the remaining spatial coincidence regions in sequence and repeat steps S21 - S22 until there is no untraversed spatial coincidence region, and obtain a composite material finite element model.

In this optional embodiment, the overall domain grid unit includes a plurality of overall domain grid nodes, and the number of nodes is not limited, including but not limited to 8 nodes of a regular hexahedron. As shown in FIG. 6 , according to the grid nodes of the overall domain Preset interpolation functions can be built.

In this optional embodiment, before constructing the preset interpolation function, the coordinates of all the first nodes of the overall domain unit may be dimensionless, so as to simplify the calculation. Dimensionless refers to the removal of some or all of the units of an equation involving a physical quantity by substituting a suitable variable. The dimensionless processing formula is as follows:

为整体域网格单元中的第i个第一节点坐标对应的无量纲自然坐标。同理可处理增强相网格单元的第二节点坐标，转化为对应的无量纲自然坐标

。Among them, as shown in Figure 6, the grid unit nodes of the overall domain are sorted by the sorting function, i is the serial number of the grid unit nodes of the overall domain, i=(1, 2, 3,...,n); (u _i , v _i , w _i ) is the ith first node coordinate of the global domain element; where Δu is the grid cell size of the global domain grid element along the horizontal axis, and Δv is the grid cell size of the global domain grid element along the vertical axis size, Δw is the grid cell size along the vertical axis of the overall domain grid;

is the dimensionless natural coordinate corresponding to the ith first node coordinate in the overall domain grid unit. Similarly, the second node coordinates of the enhanced phase grid element can be processed and converted into the corresponding dimensionless natural coordinates

.

The constructed interpolation function formula is as follows:

；

为整体域网格单元中的第i个第一节点坐标对应的无量纲自然坐标；

为第二节点坐标的无量纲自然坐标。插值函数反映了增强相节点与整体域网格单元的约束关系，是节点约束关系公式的系数。As shown in Figure 6, wherein Ni is an interpolation function, t, h, m are constants; _n is the number of first node coordinates in the overall domain grid unit, including but not limited to 8 nodes in a regular hexahedron; The overall domain grid element nodes are sorted by the sorting function, i is the serial number of the overall domain grid element node,

;

is the dimensionless natural coordinate corresponding to the ith first node coordinate in the overall domain grid unit;

is the dimensionless natural coordinate of the second node coordinate. The interpolation function reflects the constraint relationship between the enhanced phase nodes and the grid elements in the overall domain, and is the coefficient of the node constraint relationship formula.

In this optional embodiment, the node constraint relationship formula is as follows:

；（u_i，v_i，w_i）是增强相网格单元节点对应的整体域单元的第i个第一节点坐标，N_i为插值函数。根据上述公式完成选取的空间重合区域中增强相网格节点与整体域网格节点之间的节点自由度耦合。Among them, (x, y, z) are the coordinates of the enhanced phase node; as shown in Figure 6, the 8 overall domain grid unit nodes are sorted by the sorting function, i is the sequence number of the overall domain grid unit node,

; (u _i , v _i , _wi ) is the i-th first node coordinate of the integral domain element corresponding to the enhanced phase grid element node, and _Ni is the interpolation function. According to the above formula, the coupling of nodal degrees of freedom between the enhanced phase grid nodes and the overall domain grid nodes in the selected spatial coincidence region is completed.

In this optional embodiment, the traversal includes, but is not limited to, traversing the spatial coincidence region, and traversing the coordinates of the second nodes corresponding to each enhancement phase grid node in the spatial coincidence region.

In the embodiment of the present invention, the preset spatial coincidence area search algorithm searches for the overall domain grid element corresponding to the enhanced phase grid element, and performs nodal degree of freedom coupling on the two parts of the grid element through the natural interpolation function to generate the composite material finite element The model realizes the correspondence between the enhanced phase grid element and the overall domain grid element, which greatly improves the efficiency of modeling and avoids the problem of element distortion that is easy to occur in the traditional node coupling method.

Referring to FIG. 7 , taking a particle-reinforced composite material in which the matrix is pure aluminum and the reinforcing phase is B ₄ C particles as an example, the third embodiment of the finite element modeling method for the composite material in the embodiment of the present invention includes:

301. Generate a reinforcement phase geometric model and an overall domain geometric model corresponding to the composite material respectively;

In this example, the distribution parameters of B ₄ C ceramic particles are extracted to establish a reinforcement phase geometric model, and the number of particles in the composite material in which the reinforcement phase is B ₄ C ceramic particles is 30, the average particle size is 7.5um, and the volume fraction is 15 The geometric model of the reinforcement phase of B ₄ C ceramic particles generated by each distribution parameter of % is shown in Figure 2.

In this embodiment, according to the distribution parameters of the B ₄ C ceramic particle reinforcing phase including but not limited to the number of particles 30, the average particle size 7.5um, and the volume fraction 15%, the shape of the overall domain geometric model is determined to be a regular hexahedron. Preferably, a regular geometric body that can have the largest overlapping area with the enhanced phase geometric model and has the smallest volume is determined as the overall domain geometric model, which is determined as a cube here, and the size is set to a side length of 50um.

302. Based on the spatial position of the reinforcement phase in the composite material, correspondingly assemble the reinforcement phase geometric model into the overall domain geometric model to obtain a composite material geometric model;

In this embodiment, as shown in FIG. 8 , the reinforcing phase of B ₄ C ceramic particles is assembled into the monolithic domain according to the spatial positions of the B 4 C ceramic particles dispersed in the matrix.

303. Set a first mesh element size for dividing the augmented phase geometric model and a second mesh element size of the overall domain geometric model, respectively;

In this embodiment, the size of the first grid element refers to the size of the grid element divided by the enhanced phase geometric model; the second grid element size refers to the size of the grid divided by the overall domain geometric model. Preferably, the size of the first grid unit is different from the size of the second grid unit, so that the enhancement phase grid unit and the overall domain grid unit have more intersection and inclusion relationships of grid units under the condition of controlling the calculation cost. For the particle-reinforced composite material shown in FIG. 8 , taking the B ₄ C ceramic particle composite material as an example, the size of the first grid element is set to 1 um, and the size of the second grid element is set to 2 um.

304. Perform finite element mesh division on the augmented phase geometric model according to the first mesh element size, and perform finite element mesh division on the overall domain geometric model according to the second mesh element size , obtain the initial composite finite element model with the characteristics of reinforced phase mesh element and overall domain mesh element division;

In this embodiment, the grid division method includes, but is not limited to, using tetrahedral elements and regular hexahedral elements for division, and after dividing the geometric model, a mesh consisting of one or more elements such as tetrahedral mesh elements or regular hexahedral elements is obtained. lattice model. The particle-reinforced composite material shown in Figure 8, taking the B ₄ C ceramic particle composite material as an example, the tetrahedral element is used to mesh the B ₄ C ceramic particle reinforced phase geometric model, and the regular hexahedron is used to mesh the overall domain geometric model. mesh division.

305. Perform coupling processing of nodal degrees of freedom on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model in turn, to obtain a composite material finite element model.

In this embodiment, the mechanical properties of the finite element model of the composite material can be subsequently corrected according to the stiffness matrix change of the mechanical properties of the material after adding the reinforcing phase, so that the mechanical properties are equivalent to the actual mechanical properties. For example, the stiffness performance of the modified finite element model, stiffness refers to the ability of a material or structure to resist elastic deformation when it is stressed, and is a representation of the difficulty of elastic deformation of a material or structure. The stiffness of a material is usually measured by its modulus of elasticity, E. In the macroelastic range, stiffness is the proportionality factor of the material load proportional to the displacement, that is, the force required to cause a unit displacement. The stiffness matrix is the representation of stiffness under the action of various factors. The modified stiffness matrix formula is:

是修正后的复合材料有限元模型的刚度矩阵，

是增强相材料的刚度矩阵，

是基体材料的刚度矩阵。各相的刚度矩阵可以根据复合材料的性质和各相的弹性模量、泊松比等数据选取对应复合材料性质的公式进行计算获得。in,

is the stiffness matrix of the revised composite finite element model,

is the stiffness matrix of the reinforcement phase material,

is the stiffness matrix of the matrix material. The stiffness matrix of each phase can be calculated by selecting a formula corresponding to the properties of the composite material according to the properties of the composite material and the data of the elastic modulus and Poisson's ratio of each phase.

According to the properties of the composite material, different stiffness matrix calculation formulas are selected to calculate the stiffness matrix of the composite material.

和纯铝基体的刚度矩阵

，得到修正后的B₄C陶瓷颗粒增强复合材料刚度矩阵为：Take the composite material in which the reinforcing phase is B ₄ C ceramic particles and the matrix is pure aluminum as an example, the composite material is an isotropic material. Among them, the elastic modulus of the B ₄ C ceramic particles is 450,000 MPa, and the Poisson's ratio is 0.18; the elastic modulus of the pure aluminum matrix is 70,000 MPa, and the Poisson's ratio is 0.33. According to the calculation formula of the stiffness matrix of isotropic material, the stiffness matrix of B ₄ C ceramic particle reinforcement phase is calculated respectively

and the stiffness matrix of pure aluminum matrix

, the modified stiffness matrix of B ₄ C ceramic particle reinforced composites is obtained as:

After the correction, the composite material stiffness matrix represents the mechanical properties of the composite material finite element model, so that the mechanical properties of the composite material finite element model are equivalent to the actual mechanical properties.

In the embodiment of the present invention, a method of meshing the reinforcement phase geometric model and the overall domain geometric model separately is proposed to construct a composite material finite element model with coincident meshes, which avoids meshing of irregular matrix phases. , a high-quality grid cell division method is proposed, which reduces the computational cost while finely dividing the grid to ensure the accuracy of the calculation results.

Please refer to Fig. 9, taking the particle reinforced composite material whose matrix is pure aluminum and whose reinforcing phase is B ₄ C ceramic particles as an example, and a plain weave composite material whose matrix is EH301 resin material and whose reinforcing phase is T300 continuous carbon fiber bundles as an example. , the fourth embodiment of the composite material finite element modeling method in the embodiment of the present invention includes:

401. Based on the modeling method of the reinforcement phase in the composite material, generate a reinforcement phase geometric model;

In this embodiment, when the reinforcing phase is a T300 continuous carbon fiber bundle, the generated geometric model of the reinforcing phase is the geometric model of the T300 continuous carbon fiber bundle. The weaving form of T300 continuous carbon fiber bundle is plain weave. As shown in Fig. 10, c is the width of the fiber bundle, d is the gap between the fiber bundles, and e is the thickness of the fiber bundle. The parameters of the T300 continuous carbon fiber bundles were extracted to establish the reinforcement phase geometric model. Parameters include, but are not limited to, volume content of 59.2%, fiber bundle width of 1.60 mm, thickness of 0.17 mm, and gap of 0.15 mm. A sinusoidal curve is used to describe the wave shape of the fiber bundle, and a reinforcement phase geometric model for generating continuous fiber bundles is constructed.

Optionally, in an embodiment, the generating the geometric model of the reinforcement phase based on the modeling method of the reinforcement phase in the composite material includes:

If the modeling method of the reinforcement phase is to model the geometric model according to the extracted microstructure and morphology of the real composite material, the matrix geometric model in the real composite material geometric model is eliminated to obtain the reinforcement phase geometric model;

If the modeling method of the enhancement phase is to perform modeling according to the statistical data of the distribution parameters of the enhancement phase, when the enhancement phase is a particle body, a Thiessen polygon is constructed according to the distribution parameters of the enhancement phase, and the particle distribution is generated based on the Thiessen polygon. model, and the particle distribution model is used as the reinforcement phase geometric model; when the reinforcement phase is a continuous fiber bundle, a fiber weaving model is generated according to the distribution parameters of the reinforcement phase, and the fiber weaving model is used as the reinforcement phase geometric model.

In this optional embodiment, as shown in FIG. 11 , the real microstructure and morphology of the composite material in which the reinforcing phase is a granular body are shown. The real microstructure morphology of the reinforcement phase refers to the characteristics of the microstructure of the actual composite material sample, including but not limited to the particle size of the reinforcement phase microstructure, the size characteristics of the reinforcement phase particles or fibers, and the continuous fiber weave shape. According to the scanned microstructure, the real composite material geometric model is generated, including the reinforcement phase geometric model and the matrix geometric model. Elimination refers to deleting the part of the matrix geometry model in the constructed composite material geometry model, and only retains the reinforcement phase geometry model.

In this optional embodiment, the statistical data refers to the statistical data of multiple composite material samples, including but not limited to the statistical size of particle size, the statistical particle size number, the statistical distribution density, and the statistical volume content of the particle reinforcement phase. Taking the composite material whose reinforcing phase is B ₄ C ceramic particles and the matrix is pure aluminum as an example, the statistical data include but are not limited to the number of reinforcing phase particles being 30, the average particle size being 7.5um, and the volume fraction being 15%. Taking the plain weave composite material with EH301 resin material as the matrix and T300 continuous carbon fiber bundle as the reinforcing phase as an example, the statistical data include but are not limited to the volume content of 59.2%, the fiber bundle width of 1.60mm, the thickness of 0.17mm, and the gap of 0.15mm.

In this optional embodiment, the Thiessen polygon is a group of continuous polygons composed of vertical bisectors connecting two adjacent point line segments. The enhancement phase is equivalent to the control points inside the polygon, and the distance from any point in a Thiessen polygon to the control points that make up the polygon is smaller than the distance to the control points of other polygons. Taking the composite material whose reinforcing phase is B ₄ C ceramic particles and the matrix is pure aluminum as an example, the number of reinforcing phase particles is 30, the average particle size is 7.5um, and the volume fraction is 15%. According to the statistical data, the distribution points of ceramic particles are randomly generated, and as control points, a Thiessen polygon with B ₄ C ceramic particles as control points is constructed, and a particle distribution model is generated according to the constructed Thiessen polygon.

In this optional embodiment, taking a plain weave composite material whose matrix is EH301 resin material and whose reinforcing phase is T300 continuous carbon fiber bundles as an example, according to the obtained geometric parameters and distribution parameters, the modeling is performed according to the sinusoidal wave shape of T300 continuous carbon fiber bundles. The fiber weaving model shown in Figure 10 is constructed in the software.

402. Based on the morphological characteristics and distribution parameters of the reinforcement phase in the composite material, generate a global domain geometric model;

In this embodiment, the morphological characteristics of the reinforcing phase are not limited, including but not limited to particles, short fibers, plain weave fibers, twill weave fibers, and satin weave fibers.

Optionally, in an embodiment, based on the morphological characteristics and distribution parameters of the reinforcing phase in the composite material, generating the overall domain geometric model includes:

Based on the morphological characteristics of the reinforcement phase in the composite material, the geometric shape of the overall domain geometric model is determined, and based on the distribution parameters of the reinforcement phase in the composite material, the size of the overall domain geometric model is determined;

According to the determined geometric shape and size of the overall domain geometric model, the overall domain geometric model is generated.

In this optional embodiment, the geometric shape includes but is not limited to regular hexahedron, tetrahedron, cylinder, etc. Preferably, when the morphological feature of the enhanced phase is particles, a cube is selected as the geometric shape of the overall domain geometric model, when the enhanced phase morphology When the feature is a continuous fiber, a flattened cuboid is selected as the geometry of the overall domain geometry model.

In this optional embodiment, as shown in FIG. 8 , when the reinforcing phase is granular, the distribution parameters of the particle-reinforced composite material according to B ₄ C ceramic particles include the number of particles 30, the average particle size 7.5um, and the volume fraction 15% , determine that the shape of the overall domain geometry model is a cube, and the size is set to a side length of 50um. As shown in Figure 12, when the reinforcing phase adopts a sinusoidal curve to describe the fibers of the fiber wave shape, according to the distribution parameters including but not limited to the volume content of 59.2%, the fiber bundle width of 1.60mm, the thickness of 0.17mm, and the gap of 0.15mm, the fiber composite material is determined. The overall domain size is 3.52mm × 3.52mm × 0.34mm.

403. Based on the spatial position of the reinforcement phase in the composite material, correspondingly assemble the reinforcement phase geometric model into the overall domain geometric model to obtain a composite material geometric model;

404. Perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometric model in the composite material geometric model, respectively, to obtain an initial composite having the division characteristics of reinforcement phase mesh elements and overall domain mesh elements Material finite element model;

In this embodiment, as shown in FIG. 12 , when the reinforcing phase is fiber, according to the set first mesh element size for dividing the fiber-reinforced phase geometric model and the second mesh element size for dividing the overall domain geometric model , it is preferable to use hexahedral elements to perform finite element mesh division on the reinforced phase part of T300 continuous carbon fiber bundles. The size of the first mesh element is set to 0.1 mm, in particular, the size of the fiber reinforced phase along the thickness direction is set to 0.05 mm, and the size of the second mesh element is set to 0.15 mm, and a regular hexahedron is used to perform finite element analysis on the overall domain part. mesh division. Figure 12 shows, from left to right, the meshed fiber-reinforced phase geometry model, the meshed global domain geometry model, and the initial composite finite element model.

405. Perform nodal degree of freedom coupling processing on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model in turn, to obtain a composite material finite element model.

和EH301树脂基体的刚度矩阵

，得到修正后的平纹编织复合材料刚度矩阵为：In this embodiment, different stiffness matrix calculation formulas are selected according to the properties of the composite material to calculate the stiffness matrix of the composite material. Taking the composite material whose reinforcing phase is T300 continuous carbon fiber bundle and the matrix is EH301 resin material as an example, the composite material is an anisotropic material. Among them, the longitudinal elastic modulus of T300 continuous carbon fiber bundle is 171650MPa, the longitudinal shear modulus is 6700GPa, the longitudinal Poisson's ratio is 0.23, the transverse elastic modulus is 10480MPa, the transverse shear modulus is 4370MPa, and the transverse Poisson's ratio is 0.31 ; The elastic modulus of the matrix is 3450MPa, and the Poisson's ratio of the matrix is 0.3. According to the calculation formula of the anisotropic material stiffness matrix, the stiffness matrix of the T300 continuous carbon fiber bundle reinforcement phase is calculated respectively

and stiffness matrix of EH301 resin matrix

, the modified stiffness matrix of plain weave composites is:

After the correction, the composite material stiffness matrix represents the mechanical properties of the composite material finite element model, so that the mechanical properties of the composite material finite element model are equivalent to the actual mechanical properties. The modification of the composite material in which the reinforcing phase is B ₄ C ceramic particles and the matrix is pure aluminum has been described in Example 3, and will not be repeated here.

In the embodiment of the present invention, it is described that the enhanced phase geometric model is generated by the collected distribution parameters, then the overall domain geometric model is generated according to the enhanced phase geometric model, and the enhanced phase geometric model is assembled into the overall domain geometric model. And after the finite element model of composite material is constructed, the mechanical properties of the finite element model are also corrected. This method avoids the model construction of the irregular matrix and the subsequent finite element mesh division, reduces the computational cost, and makes the mechanical properties of the composite finite element model equivalent to that of the actual composite material, and the simulation results are more accurate.

The composite material finite element modeling method in the embodiment of the present invention has been described above, and the composite material finite element system in the embodiment of the present invention is described below. Please refer to FIG. 13. An embodiment of the composite material finite element system in the embodiment of the present invention includes: :

The model generation module 501 is used to respectively generate the reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material;

A model assembling module 502, configured to assemble the geometric model of the reinforcing phase into the overall domain geometric model correspondingly based on the spatial position of the reinforcing phase in the composite material, to obtain a geometric model of the composite material;

The meshing module 503 is configured to perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometry model in the composite material geometric model respectively, to obtain a mesh unit with reinforcement phase and an overall domain mesh The initial composite finite element model of element division features;

The nodal coupling module 504 is configured to sequentially perform nodal degree of freedom coupling processing on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model to obtain a composite material finite element model.

In the embodiment of the present invention, a finite element modeling system for composite materials is provided. When constructing the geometric model of the composite material, the overall domain is used instead of the matrix for modeling, and the reinforcement phase geometric model and the overall domain geometric model are respectively generated, and then the The two geometric models are assembled to obtain the composite material geometric model; then the reinforced phase part and the overall domain part of the composite material geometric model are separately meshed with finite element, and the corresponding multiple reinforced phase mesh elements and overall domain network are obtained. Then, the coupling processing of nodal degrees of freedom is performed on the spatial coincidence area of the reinforcement phase mesh element and the overall domain mesh element in turn, and the final composite finite element model is obtained. The invention introduces the concept of the overall domain, and through the finite element mesh division of the overall domain, various finite element meshing problems caused by the direct finite element meshing of the matrix with complex spatial configuration are avoided, and at the same time, the The independent mesh division of the phase geometry model and the overall domain geometry model is enhanced, and the correlation between the mesh divisions of the two is reduced, so that the finite element modeling accuracy is controllable, and the premise of ensuring the accuracy of the finite element modeling of composite materials is realized. Therefore, the time cost of simulation calculation is reduced.

Referring to FIG. 14, another embodiment of the composite material finite element modeling system in the embodiment of the present invention includes:

The model generation module 501 is used to respectively generate the reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material;

A model assembling module 502, configured to assemble the geometric model of the reinforcing phase into the overall domain geometric model correspondingly based on the spatial position of the reinforcing phase in the composite material, to obtain a geometric model of the composite material;

The meshing module 503 is configured to perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometry model in the composite material geometric model respectively, to obtain a mesh unit with reinforcement phase and an overall domain mesh The initial composite finite element model of element division features;

The nodal coupling module 504 is configured to sequentially perform nodal degree of freedom coupling processing on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model to obtain a composite material finite element model.

Optionally, the meshing module 503 further includes:

a size setting unit 5031, configured to respectively set the size of the first mesh element used to divide the augmented phase geometric model and the second mesh element size of the overall domain geometric model;

A mesh division unit 5032, configured to perform finite element mesh division on the augmented phase geometric model according to the first mesh element size, and perform finite element mesh division on the overall domain geometric model according to the second mesh element size The finite element meshing is carried out to obtain the initial composite finite element model with the characteristics of reinforced phase mesh element and overall domain mesh element division.

Optionally, the node coupling module 504 further includes:

A coincidence area search unit 5041, configured to search for a spatial coincidence area where the overall domain grid unit includes the enhancement phase grid unit;

The node coupling unit 5042 is used to set the node constraint relationship between the reinforcement phase grid unit and the overall domain grid unit in the spatial coincidence area, and perform nodal degree of freedom coupling processing based on the node constraint relationship to obtain a composite material finite element model .

Further optionally, each of the overall domain grid units includes a plurality of overall domain grid nodes, each of the enhancement phase grid units includes a plurality of enhancement phase grid nodes, and the coincidence area search unit 5041 further includes:

The numbering subunit is used to traverse all the overall domain grid units, number the overall domain grid nodes where each overall domain grid unit is in the same position, obtain the unit number of each overall domain grid unit, and assign the numbered overall domain grid unit The first node coordinates of the grid nodes are stored in association with the unit number;

The rounding subunit is used to select any enhancement phase grid node, obtain the second node coordinates of the enhancement phase grid node, and perform a rounding algorithm on the second node coordinates to obtain the comparison coordinates;

The confirmation subunit is used to calculate the two-norm of the comparison coordinates and the first node coordinates of the overall domain grid nodes of each number respectively, obtain the first node coordinates corresponding to the minimum two-norm, and read the first node The unit number corresponding to the coordinate, the overall domain grid unit corresponding to the unit number is the spatial coincidence area containing the enhancement phase grid unit;

The first traversal subunit is used for traversing the remaining enhancement phase grid nodes in sequence and repeatedly executing the rounding subunit and the confirmation subunit until there are no untraversed enhancement phase grid nodes.

Further optionally, each of the overall domain grid units includes a plurality of overall domain grid nodes, each of the enhanced phase grid units includes a plurality of enhanced phase grid nodes, and the node coupling unit 5042 further includes :

Selecting subunits for selecting the first node coordinates corresponding to each overall domain grid node and the second node coordinates corresponding to each enhancement phase grid node in any spatial coincidence region;

Substitute into a subunit, for sequentially substituting the selected one second node coordinate and all first node coordinates into the preset interpolation function, and based on the interpolation function, construct the node constraint relationship, and complete the enhanced phase grid in the selected spatial coincidence area Nodal degrees of freedom coupling between nodes and global domain mesh nodes;

The second traversing subunit is used for traversing the remaining spatial coincidence regions in sequence and repeating the selection subunit and the substitution subunit until there is no untraversed spatial coincidence region to obtain a composite material finite element model.

Optionally, the model generation module 501 further includes:

The reinforcement phase model unit 5011 is used to generate the reinforcement phase geometric model based on the modeling method of the reinforcement phase in the composite material;

The overall domain model unit 5012 is configured to generate an overall domain geometric model based on the morphological characteristics and distribution parameters of the reinforcement phase in the composite material.

Further optionally, the reinforcement phase model unit 5011 can also be specifically used for: if the modeling method of the reinforcement phase is to perform geometric model modeling according to the extracted microstructure and morphology of the real composite material, then remove the geometric model of the real composite material. Geometric model of the matrix to obtain the geometric model of the enhanced phase;

If the modeling method of the enhancement phase is to perform modeling according to the statistical data of the distribution parameters of the enhancement phase, when the enhancement phase is a particle body, a Thiessen polygon is constructed according to the distribution parameters of the enhancement phase, and the particle distribution is generated based on the Thiessen polygon. model, and the particle distribution model is used as the reinforcement phase geometric model; when the reinforcement phase is a continuous fiber bundle, a fiber weaving model is generated according to the distribution parameters of the reinforcement phase, and the fiber weaving model is used as the reinforcement phase geometric model.

Preferably, the overall domain model unit 5012 can also be used to:

Based on the morphological characteristics of the reinforcement phase in the composite material, the geometric shape of the overall domain geometric model is determined, and based on the distribution parameters of the reinforcement phase in the composite material, the size of the overall domain geometric model is determined;

According to the determined geometric shape and size of the overall domain geometric model, the overall domain geometric model is generated.

In the embodiment of the present invention, a composite material finite element modeling system is provided, which uses the overall domain instead of the matrix for modeling, generates the reinforcement phase geometric model and the overall domain geometric model, and separately analyzes the reinforcement phase part of the composite material geometric model. Perform finite element meshing with the overall domain part to obtain a plurality of corresponding enhanced phase mesh elements and overall domain mesh elements, and then perform nodal degree of freedom coupling on the spatial coincidence region of the enhanced phase mesh element and the overall domain mesh element in turn. process to obtain the final composite finite element model. This modeling system avoids the direct finite element mesh division of the irregular matrix phase, reduces the correlation between the two mesh divisions, and makes the finite element modeling accuracy controllable. High-quality mesh elements are obtained, and the time cost of simulation calculation is reduced on the premise of ensuring the accuracy of finite element modeling of composite materials.

The present invention also provides a computer-readable storage medium. The computer-readable storage medium may be a non-volatile computer-readable storage medium. The computer-readable storage medium may also be a volatile computer-readable storage medium. The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to execute the steps of the method for finite element modeling of composite materials.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, for the specific working process of the system described above, reference may be made to the corresponding process in the foregoing method embodiments, which will not be repeated here.

The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: The technical solutions described in the embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (12)

1. a composite material finite element modeling method, is characterized in that, described composite material finite element modeling method comprises: The reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material are generated respectively; Based on the spatial position of the reinforcing phase in the composite material, correspondingly assembling the reinforcing phase geometric model into the overall domain geometric model to obtain a composite material geometric model; Perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometry model in the composite material geometric model respectively, and obtain an initial composite material with the characteristics of reinforcement phase mesh element and overall domain mesh element division. metamodel; searching for all spatially coincident regions where the overall domain grid cell includes the enhancement phase grid cell; Setting the node constraint relationship of the reinforcement phase mesh element and the overall domain mesh element in each of the spatial coincidence regions respectively, completing the coupling of the nodal degrees of freedom, and obtaining the composite material finite element model; Wherein, each of the overall domain grid cells includes a plurality of overall domain grid nodes, each of the enhancement phase grid cells includes a plurality of enhancement phase grid nodes, and the searching for the overall domain grid cells includes: The spatial coincidence region of the enhancement phase grid unit includes: Step S11, traverse all the overall domain grid units, number the overall domain grid nodes where each overall domain grid unit is in the same position, obtain the unit number of each overall domain grid unit, and assign the numbered overall domain grid nodes The coordinates of the first node are stored in association with the unit number; Step S12, select any enhancement phase grid node, obtain the second node coordinates of the enhancement phase grid node, and perform a rounding algorithm on the second node coordinates to obtain the comparison coordinates; Step S13: Calculate the two-norm of the comparison coordinates and the first node coordinates of the overall domain grid nodes of each number respectively, obtain the first node coordinates corresponding to the minimum two-norm, and read the corresponding first node coordinates. The unit number, the overall domain grid unit corresponding to the unit number is the spatial coincidence area containing the enhancement phase grid unit; Step S14, traverse the remaining enhancement phase grid nodes in turn and repeat steps S12-S13 until there are no untraversed enhancement phase grid nodes; Among them, the comparison coordinates are calculated by the rounding algorithm, and the formula of the rounding algorithm is as follows:

in

is the grid cell size along the horizontal axis of the overall domain grid cells,

is the grid cell size along the vertical axis of the global domain grid cells,

is the grid cell size along the vertical axis of the overall domain grid,

represent the coordinates of the enhancement phase mesh element nodes,

Indicates the comparison coordinates, k, p, q are constants. 2 . The method for finite element modeling of composite materials according to claim 1 , wherein the finite element network is respectively performed on the reinforcement phase geometric model and the overall domain geometric model in the composite material geometric model. 3 . Mesh division, and the initial composite finite element model with the characteristics of reinforcement phase mesh element and overall domain mesh element division includes: respectively setting a first mesh element size for dividing the augmented phase geometric model and a second mesh element size of the overall domain geometric model; According to the first mesh element size, the reinforcement phase geometric model is subjected to finite element mesh division, and according to the second mesh element size, the overall domain geometric model is subjected to finite element mesh division to obtain Initial composite finite element model with enhanced phase mesh elements and integral domain mesh elements. 3 . The finite element modeling method of composite materials according to claim 1 , wherein each of the overall domain mesh elements comprises a plurality of overall domain mesh nodes, and each of the reinforcement phase mesh elements includes A plurality of reinforcement phase mesh nodes, the node constraint relationship between the reinforcement phase mesh element and the overall domain mesh element in each of the spatially overlapping regions is respectively set, and the coupling of the degrees of freedom of the nodes is completed, and the obtained composite material finite element model includes: Step S21, selecting the first node coordinates corresponding to each overall domain grid node and the second node coordinates corresponding to each enhancement phase grid node in any spatial coincidence region; Step S22: Substitute a selected second node coordinate and all first node coordinates into a preset interpolation function in turn, and build a node constraint relationship based on the interpolation function, and complete the enhanced phase grid node in the selected spatial overlap region and the whole. Nodal degrees of freedom coupling between domain mesh nodes; Step S23, traverse the remaining spatial coincidence regions in sequence and repeat steps S21-S22 until there is no untraversed spatial coincidence region, and obtain a composite material finite element model. 4. The method for finite element modeling of composite materials according to claim 1, wherein the step of respectively generating the reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material comprises: Based on the modeling method of the reinforcing phase in the composite material, the geometric model of the reinforcing phase is generated; Based on the morphological characteristics and distribution parameters of the reinforcement phase in the composite material, a global domain geometry model is generated. 5 . The finite element modeling method of composite materials according to claim 4 , wherein, generating the geometric model of the reinforcement phase based on the modeling method of the reinforcement phase in the composite material comprises: 6 . If the modeling method of the reinforcement phase is to model the geometric model according to the extracted microstructure and morphology of the real composite material, the matrix geometric model in the real composite material geometric model is eliminated to obtain the reinforcement phase geometric model; If the modeling method of the enhancement phase is to perform modeling according to the statistical data of the distribution parameters of the enhancement phase, when the enhancement phase is a particle body, a Thiessen polygon is constructed according to the distribution parameters of the enhancement phase, and the particle distribution is generated based on the Thiessen polygon. model, and the particle distribution model is used as the reinforcement phase geometric model; when the reinforcement phase is a continuous fiber bundle, a fiber weaving model is generated according to the distribution parameters of the reinforcement phase, and the fiber weaving model is used as the reinforcement phase geometric model. 6. The composite material finite element modeling method according to claim 4 or 5, wherein the generating the overall domain geometric model based on the morphological characteristics and distribution parameters of the reinforcing phase in the composite material comprises: Based on the morphological characteristics of the reinforcement phase in the composite material, the geometric shape of the overall domain geometric model is determined, and based on the distribution parameters of the reinforcement phase in the composite material, the size of the overall domain geometric model is determined; According to the determined geometric shape and size of the overall domain geometric model, the overall domain geometric model is generated. 7. A composite material finite element modeling system, wherein the composite material finite element modeling system comprises: The model generation module is used to respectively generate the reinforcement phase geometric model and the overall domain geometric model corresponding to the composite material; a model assembling module, configured to assemble the geometric model of the reinforcing phase into the overall domain geometric model correspondingly based on the spatial position of the reinforcing phase in the composite material, to obtain a geometric model of the composite material; A meshing module is used to perform finite element mesh division on the reinforcement phase geometric model and the overall domain geometry model in the composite material geometric model respectively, so as to obtain a mesh element with reinforcement phase and an overall domain mesh element The initial composite finite element model of the partitioned features; The nodal coupling module is used to sequentially perform nodal degree of freedom coupling processing on the spatial coincidence region of the reinforcement phase mesh element and the overall domain mesh element in the initial composite material finite element model to obtain the composite material finite element model; Wherein, the node coupling module includes: a coincidence area search unit, configured to search for a spatial coincidence area where the overall domain grid unit includes the enhancement phase grid unit; a node coupling unit, used to set the node constraint relationship between the enhanced phase grid unit and the overall domain grid unit in the spatial coincidence region, and perform nodal degree of freedom coupling processing based on the node constraint relationship to obtain a composite material finite element model; Wherein, each of the overall domain grid units includes a plurality of overall domain grid nodes, each of the enhancement phase grid units includes a plurality of enhancement phase grid nodes, and the coincidence area search unit includes: The numbering subunit is used to traverse all the overall domain grid units, number the overall domain grid nodes where each overall domain grid unit is in the same position, obtain the unit number of each overall domain grid unit, and assign the numbered overall domain grid unit The first node coordinates of the grid nodes are stored in association with the unit number; The rounding subunit is used to select any enhancement phase grid node, obtain the second node coordinates of the enhancement phase grid node, and perform a rounding algorithm on the second node coordinates to obtain the comparison coordinates; The confirmation subunit is used to respectively calculate the two-norm of the first node coordinates of the comparison coordinates and the overall domain grid nodes of each number, obtain the first node coordinates corresponding to the minimum two-norm, and read the first node The unit number corresponding to the coordinate, the overall domain grid unit corresponding to the unit number is the spatial coincidence area containing the enhancement phase grid unit; The first traversal subunit is used to traverse the remaining enhancement phase grid nodes in sequence and repeatedly execute the rounding subunit and the confirmation subunit until there is no untraversed enhancement phase grid node; Among them, the comparison coordinates are calculated by the rounding algorithm, and the formula of the rounding algorithm is as follows:

in

is the grid cell size along the horizontal axis of the overall domain grid cells,

is the grid cell size along the vertical axis of the global domain grid cells,

is the grid cell size along the vertical axis of the overall domain grid,

represent the coordinates of the enhancement phase mesh element nodes,

Indicates the comparison coordinates, k, p, q are constants. 8. The composite material finite element modeling system according to claim 7, wherein the meshing module comprises: a size setting unit, configured to respectively set the size of the first mesh element used to divide the reinforcement phase geometric model and the second mesh element size of the overall domain geometric model; a meshing unit for performing finite element meshing on the reinforcement phase geometric model according to the first mesh element size, and performing finite element meshing on the overall domain geometric model according to the second mesh element size The finite element mesh is divided to obtain the initial composite finite element model with the characteristics of the reinforcement phase mesh element and the overall domain mesh element division. 9. The composite material finite element modeling system according to claim 7, wherein the node coupling module comprises: a coincidence area search unit, configured to search for a spatial coincidence area where the overall domain grid unit includes the enhancement phase grid unit; The nodal coupling unit is used to set the nodal constraint relationship between the enhanced phase grid unit and the overall domain grid unit in the spatial coincidence region, and perform nodal degree of freedom coupling processing based on the nodal constraint relationship to obtain a composite material finite element model. 10 . The finite element modeling system for composite materials according to claim 9 , wherein each of the overall domain mesh elements comprises a plurality of overall domain mesh nodes, and each of the reinforcement phase mesh elements includes A plurality of enhanced phase grid nodes, the coincidence area search unit includes: The numbering subunit is used to traverse all the overall domain grid units, number the overall domain grid nodes where each overall domain grid unit is in the same position, obtain the unit number of each overall domain grid unit, and assign the numbered overall domain grid unit The first node coordinates of the grid nodes are stored in association with the unit number; The rounding subunit is used to select any enhancement phase grid node, obtain the second node coordinates of the enhancement phase grid node, and perform a rounding algorithm on the second node coordinates to obtain the comparison coordinates; The confirmation subunit is used to calculate the two-norm of the comparison coordinates and the first node coordinates of the overall domain grid nodes of each number respectively, obtain the first node coordinates corresponding to the minimum two-norm, and read the first node The unit number corresponding to the coordinate, the overall domain grid unit corresponding to the unit number is the spatial coincidence area containing the enhancement phase grid unit; The first traversal subunit is used for traversing the remaining enhancement phase grid nodes in sequence and repeatedly executing the rounding subunit and the confirmation subunit until there are no untraversed enhancement phase grid nodes. 11. The composite material finite element modeling system according to claim 9 or 10, wherein each of the overall domain mesh elements comprises a plurality of overall domain mesh nodes, and each of the reinforcement phase meshes The element includes a plurality of enhanced phase mesh nodes, and the node coupling element includes: Selecting subunits for selecting the first node coordinates corresponding to each overall domain grid node and the second node coordinates corresponding to each enhancement phase grid node in any spatial coincidence region; Substitute into a subunit, for sequentially substituting the selected one second node coordinate and all first node coordinates into the preset interpolation function, and based on the interpolation function, construct the node constraint relationship, and complete the enhanced phase grid in the selected spatial coincidence area Nodal degrees of freedom coupling between nodes and global domain mesh nodes; The second traversing subunit is used for traversing the remaining spatial coincidence regions in sequence and repeating the selection subunit and the substitution subunit until there is no untraversed spatial coincidence region to obtain a composite material finite element model. 12. A computer-readable storage medium on which instructions are stored, wherein the instructions are executed by a processor to realize the composite material according to any one of claims 1-6 Finite Element Modeling Methods.

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