CN205439386U - Honeycomb sandwich plate - Google Patents

Abstract

The utility model discloses a honeycomb sandwich panel, which comprises an upper panel, a lower panel and a honeycomb grid in the middle. The honeycomb grid is a hexagonal, quadrilateral or triangular grid, and the There are circular arc pieces, and the circular arc pieces in the corners with the common side as the vertex on all the honeycomb grids that share one side are connected to form a cylinder. The ends are flush and integrated. The sandwich panel structure of the utility model effectively enhances the compressive performance, bending resistance and elastic deformation performance of the honeycomb panel. The result is lightweight, high-strength sandwich panels that are suitable for use in building long-span roofs, exterior wall structures, automobiles, and aerospace.

Description

A kind of honeycomb sandwich panel

technical field

The utility model relates to a honeycomb panel, which belongs to the technical field of hollow plate processing.

Background technique

Today, when energy saving and environmental protection have become the main evaluation index of products, the research of new light-weight structures has attracted people's attention. Honeycomb sandwich panel has become one of the indispensable structures in aviation, aerospace, railway, automobile, construction and other fields due to its light weight, high rigidity and strong designability. Due to the high production cost at the beginning, it has been mainly used in the aerospace field since the 1950s. Later, with the advancement of science and technology, the improvement of process methods was gradually applied to other industrial fields. The materials for making honeycomb panels include paper, composite materials, metal, etc. The characteristics of light weight and high strength of honeycomb panels are mainly due to the thin-walled structure of the middle core layer. However, since the use of honeycomb panels, it may be because the honeycomb wall is already very thin (such as aluminum, paper, and some are below 0.01 mm), there is almost no improvement for the thin-walled honeycomb structure, and most of the improvements are new composite materials. Honeycomb panels, such as chiral honeycomb panels, integrated honeycomb panels. Therefore, for decades, the thin-walled honeycomb core structure has basically been a simple honeycomb core layer structure, or only changes in the shape of hexagons, squares, etc., or changes in size, and there has been almost no improvement in the structure of the honeycomb core, thus As a result, its various mechanical properties have not been improved, and it has not followed the development of modern technology and developed greater application potential of honeycomb panels.

Contents of the invention

The technical problem to be solved by this utility model is aimed at the deficiencies in the above-mentioned prior art. Inspired by the existence of small pillars in the honeycomb structure of some organisms—its outer layer is fiber and the core layer is protein, the honeycomb—cylindrical structure is extracted. Model, and verified by calculation, provides a honeycomb panel with better mechanical properties under the same mass.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:

A honeycomb sandwich panel, comprising an upper panel, a lower panel and a honeycomb grid in the middle, the honeycomb grid is a hexagonal, quadrangular or triangular grid, characterized in that: it is arranged in each corner of all the honeycomb grids There are circular arcs, and the circular arcs located in different honeycomb grids centered on the apex of each corner are connected to form a cylinder, and the end face of the cylinder is flush with and connected to the end face of the honeycomb grid where the cylinder is located. into one. Moreover, the side length of the grid and the diameter of the inscribed circle can be changed according to actual engineering requirements.

The radius of the cylinder is 1/4-1/2 of the side length of the honeycomb grid, and the thickness of the cylinder is 0.5-2 times the thickness of the honeycomb grid. The specific multiple is taken according to the actual project.

One end of the cylinder is provided with a first slot for insertion of the side of the honeycomb grid, and a second slot for insertion of the cylinder is provided on the side of the honeycomb grid.

The cylinder is composed of circular arc pieces respectively fixed in each honeycomb grid.

The cylinder and the honeycomb grid are integrally formed.

The upper panel is a flat panel or a curved panel.

The lower panel is a flat panel or a curved panel.

The honeycomb interlayer board of the utility model is a sandwich strengthening board with a polygonal grid in the middle. Including upper panel, lower panel and middle layer grid. At all grid intersections, there is a cylinder with the intersection line as the center and fixedly connected with the honeycomb grid. The end face of the cylinder is flush with the end face of the honeycomb grid where the cylinder is located and integrated. , and the side length of the grid and the diameter of the inscribed circle can be changed according to the actual engineering requirements. One or more cylinders can also be set in each polygonal grid according to actual engineering. The polygonal grid structure can be a regular hexagonal grid or other polygons, and these grids are closely arranged. Honeycomb is one of the structural forms. Materials for making honeycomb panels can be metal, paper, etc. according to actual engineering needs. It can be seen from the above that the sandwich panel made of the honeycomb structure with a cylinder can significantly improve its compressive performance, bending resistance and elastic deformation performance compared with the traditional sandwich panel. It is a light weight, high strength bionic structure. In fact, the honeycomb wall thickness of the middle core layer of many honeycomb panels is relatively thin compared to the panel. However, the utility model can improve the mechanical properties of traditional honeycomb panels, especially thin-walled honeycomb panels. Therefore the utility model has very wide application prospect. It can be used in the fields of building long-span roofs, exterior wall structures, ships, automobiles, and aerospace.

The utility model arranges a cylindrical structure at the intersection of the honeycomb walls, and the structure plays the following three strengthening functions: 1. The cylindrical structure has better mechanical properties compared with the honeycomb walls of equal cross-section; 2. The cylindrical structure improves the honeycomb structure. The out-of-plane constraint of the panel enhances the bending resistance of the panel itself; 3. The cylindrical structure constrains the honeycomb wall connected to it and the intersection of the honeycomb wall, thereby improving the mechanical properties of the honeycomb panel. Therefore, the honeycomb sandwich panel of the utility model can effectively improve various mechanical performance indexes such as compressive performance, bending resistance performance and elastic deformation performance of the honeycomb panel. The applicant conducted three-dimensional finite element analysis on the above-mentioned cylinder-honeycomb plate structure, and found that under the condition of the same mass and volume of the honeycomb plate, the mechanical properties of the cylinder-honeycomb plate structure can be improved on average compared with the traditional thin-walled honeycomb plate. 15%, some mechanical properties can be improved by 30-40%.

Description of drawings

Fig. 1 is the utility model structure and size schematic diagram; Wherein (a) perspective view, (b) top view;

Fig. 2 is the structural representation of core layer and base plate in Fig. 1;

Fig. 3 is the schematic diagram of compression model and compression test;

Figure 4 is the load-displacement curve of the compression test;

Fig. 5 is the schematic diagram of bending model and bending test;

Figure 6 is the load-displacement curve of the bending test;

Fig. 7 is a schematic diagram of making a cylindrical honeycomb panel by buckle method;

Figure 8 is a schematic diagram of making a cylindrical honeycomb panel by pasting;

Fig. 9 is a case where the honeycomb grid is other polygons; wherein (a) the honeycomb grid is a quadrilateral, and (b) the honeycomb grid is a triangle.

Among them: 1 is the lower panel; 2 is the cylinder; 3 is the honeycomb wall; 4 is the upper panel; 5 is the first slot; 6 is the second slot; 7 is the arc sheet.

detailed description

Below in conjunction with accompanying drawing, the utility model is described in detail:

As shown in FIG. 1 , the honeycomb sandwich panel of the present invention includes an upper panel 4 , a lower panel 1 , a honeycomb grid in the middle and a cylinder 2 . In this embodiment, the honeycomb grid is a regular hexagonal grid, and each side of the regular hexagonal grid is a honeycomb wall 3 . In the plane, all adjacent regular hexagons have a common side, and all adjacent regular hexagons have two common endpoints, and these two common endpoints are located at the two ends of the common side. The end point is provided with a cylindrical structure centered on the end point and distributed in three hexagonal grids with the end point as the intersection point. The end face of the cylinder is flush with the end face of the connected hexagonal grid, And the grid side length and the diameter of the inscribed circle can be changed according to the actual engineering requirements. Both the upper panel and the lower panel can be flat panels or curved panels.

The radius of the cylinder is 1/4-1/2 of the side length of the honeycomb grid, and the thickness of the cylinder is 0.5-2 times the thickness of the honeycomb grid. The specific multiple is taken according to the actual project.

At present, the production methods of traditional honeycomb panels mainly include three methods: tensioning method, pasting method and integral molding. The production method of the cylindrical honeycomb panel of the utility model is improved on the basis of the production of the traditional honeycomb panel, and now three production methods are proposed:

1 Buckle method: according to the size requirements of the honeycomb panel, reserve the first slot 5 on the honeycomb wall. The cylinder 2 at the intersection of the honeycomb walls also reserves a second card slot 7 at the corresponding position. First make the honeycomb panel according to the traditional honeycomb panel manufacturing method (tensioning method and pasting method), and then connect the prefabricated cylindrical member to the honeycomb panel through the second clamping groove 7 (as shown in Figure 7). In order to ensure that the two work together, glue can be applied to the first slot and the second slot before the cylinder is fastened to ensure their connection.

2 Pasting method: The production method of the honeycomb panel is the same as that of the buckle type. The difference is that the cylinder 2 is equally divided into circular arc pieces 8 when making the cylinder member. After the traditional honeycomb panel is finished, the arc sheet 8 is connected to the honeycomb wall by glue (as shown in Figure 8).

3 Integral molding: For many special industries or fields, such as aerospace, automobile manufacturing, shipbuilding, and industries that require relatively high overall performance of honeycomb panels, cylindrical honeycomb panels can be made by integral molding to ensure their good mechanical properties. And according to the aforementioned analysis of the bending performance of the cylindrical honeycomb panel, the integrally formed honeycomb panel has good deformation energy dissipation and resistance to dynamic load or fatigue load.

The schematic diagram of the model of the honeycomb panel is shown in Figures 1 and 2. The size of the honeycomb panel in this manual is set according to the large-span roof structure in the construction industry. The material is 7075 aluminum alloy, and a cylinder is set at each grid intersection. See Table 1 and Table 2 for detailed dimensions. Among them, R and r refer to the radius of the inscribed circle of the regular hexagon and the radius of the small column respectively; T and t refer to the thickness of the cylinder and the thickness of the honeycomb wall respectively; H and h refer to the overall height of the honeycomb panel and the height of the core layer respectively; B and L refer to The width and length of the honeycomb panel.

Table 1 Dimensions of honeycomb panel compression model (in mm)

model type R t r T h L B h model 1 3 0.1 0 0 8 230 60 10 model 2 6 0.1 2 0.1 8 230 60 10

Table 2 Dimensions of honeycomb panel bending model (in mm)

model type R t r T h L B h model 1 3 0.1 0 0 8 60 60 10 model 2 6 0.1 2 0.1 8 60 60 10

The compression and four-point bending test simulations of traditional honeycomb panels (Model 1) and cylindrical honeycomb panels (Model 2) were performed using the finite element analysis software ABAQUS with very powerful nonlinear functions. By applying a displacement load to the honeycomb panels at a speed of 0.1 mm/min, the load-displacement curves of the two honeycomb panels were obtained. Among them, the compression test is based on the compressive stiffness and compressive strength calculated from the above data to illustrate the compression performance of the cylindrical honeycomb panel and the traditional honeycomb panel; the simulated span of the four-point bending test is uniformly 210mm, and the load loading position is at the third level of the span points. According to the above data, the specific strength and bending strength of the honeycomb panel are calculated to illustrate the bending performance of the cylindrical honeycomb panel and the traditional honeycomb panel. When modeling the honeycomb panels, it has been ensured that the core layer of the two honeycomb panels has the same volume as the panel, so the above four performance indicators are compared under the condition that the two honeycomb panels have the same mass and volume, except for the core layer structure , other factors being the same, so it is more representative.

Through ABAQUS analysis (see the compression model in Figure 3), a displacement load is applied to the honeycomb panel along the direction vertical to the honeycomb panel surface at a speed of 0.1mm/min and the bottom plate of the honeycomb panel is fixed, and the load-displacement curve is shown in Figure 4. And calculate the compressive stiffness and compressive strength in the compressed state according to formula 1,2.

$\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; f</span>}}{\mathrm{<span\; class="notranslate">\; D.</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}$

$\mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}}{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}$

In the formula: K—compressive stiffness, unit N/m

F—the maximum load of elastic deformation, unit N

D—the maximum displacement of elastic deformation, in m

A—the area of the upper panel of the honeycomb, in ^m2

σ—compressive stress, unit Pa

F _max — the maximum load value during compression, unit N

Compressive stiffness refers to the ability of an object to resist compression deformation under the action of an external force, and is measured by the value of the external force required to produce a unit deformation. The value of compressive stiffness in this analysis is equal to the slope of the linear part of the load-displacement curve. Compressive strength refers to the ability of an object to resist compression damage under external force, where F _max is the maximum load during compression.

Table 3 Compression test data

model type R t r T h L B h K(MN/mm) σ(MPa) model 1 3 0.1 0 0 8 60 60 10 1.095 12.250 model 2 6 0.1 2 0.1 8 60 60 10 1.259 13.949

Figure 4 is the load-displacement curve obtained from the analysis of the finite element software. Based on this, the compressive stiffness and compressive strength of the cylindrical honeycomb panel and the traditional honeycomb panel are calculated. It can be obtained from Table 3 that the above two indicators of the cylindrical honeycomb panel are 15.0% and 13.9% higher than the traditional honeycomb panel respectively. And it can be seen from Figure 4 that when the two kinds of honeycomb panels reach the ultimate load, the curve decline of the cylindrical honeycomb panel is much smaller than that of the traditional honeycomb panel. When the displacement reaches 0.5mm, the load value that the two honeycomb panels can bear differs by 45%. It shows that even if the cylindrical honeycomb panel has a large displacement, it can still bear a larger load than the traditional honeycomb panel.

Through ABAQUS analysis (see Figure 5 bending model), the displacement load is applied to the honeycomb panel along the direction perpendicular to the honeycomb panel surface at a speed of 0.1mm/min, and the load-displacement curve is shown in Figure 6, and according to formulas 3 and 4 Calculate the specific strength in the elastic range in bending and the flexural strength at failure.

$\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; P</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}$

$\mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}\mathrm{<span\; class="notranslate">\; l</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; BH</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 4</span>}$

In the formula: S—specific strength, unit N m/kg

P—the maximum load of elastic deformation, unit N

—The equivalent density of the honeycomb panel, unit N m/kg; where t _f is the thickness of the panel, δ _c is the thickness of the honeycomb wall, a is the length of a single honeycomb wall, h is the height of the honeycomb core layer, and ρ _f is the density of the honeycomb panel material. The volume of the core layer of the two types of honeycomb panels is the same, so ρ takes the same value

σ—bending stress, unit Pa

F _max — total maximum load when subjected to bending, unit N

B—width of honeycomb panel, unit m

H—height of honeycomb panel, unit m

The specific strength refers to the bearing capacity of the structure under the condition of equal quality, and the larger the value, the better the performance. Since the main difference between the two honeycomb panels is reflected in the elastic stage, as shown in Figure 6, the black dots in the curve represent the turning point when the traditional honeycomb panel and the cylindrical honeycomb panel enter the plastic stage from the elastic stage. It can be seen that the elastic strain of the traditional honeycomb panel is 4.8% during bending deformation, while that of the cylindrical honeycomb panel is 7.3%. That is, the elastic deformation capacity of the cylindrical honeycomb panel is 1.5 times that of the traditional honeycomb panel. It means that in addition to better bending resistance, the cylindrical honeycomb panel also has good deformation energy dissipation and dynamic load resistance. Therefore, the load in the specific strength takes the maximum value of the load during elastic deformation. Bending strength refers to the ability of an object to resist bending damage under the action of an external force, and the maximum value of the load at the time of damage is taken.

Table 4 bending test data

model type R t r T h L B h S(N·m/kg) σ(MPa) model 1 3 0.1 0 0 8 230 60 10 7.63 378.5 model 2 6 0.1 2 0.1 8 230 60 10 10.81 423.8

Figure 6 is the load-displacement curve obtained from the analysis of the finite element software. Based on this, the specific strength of the cylindrical honeycomb panel and the traditional honeycomb panel in the elastic state and the bending strength at the time of failure are calculated. It can be obtained from Table 4 that the above two indicators of the cylindrical honeycomb panel are 41.7% and 12.0% higher than the traditional honeycomb panel respectively. From the above comparison, it can be clearly concluded that the cylindrical honeycomb panel has better bending resistance than the traditional honeycomb panel. More importantly, the cylindrical honeycomb panel has better elastic deformation ability. It can be predicted that the dynamic performance of the honeycomb panel (anti-fatigue ability, anti-deformation ability, ability to resist vibration load, etc.) will have excellent performance.

Claims (7)

1. a honeycomb sandwich panel, honeycomb grid including top panel, lower panel and centre, described honeycomb grid is hexagon, tetragon or triangular lattice, it is characterized in that: in each angle of all honeycomb grid, be provided with arc plate, the arc plate being positioned at different honeycomb grid centered by the summit at each angle connects into a cylinder, and the end face of this cylinder is concordant with the end face of the honeycomb grid of cylinder position and is connected.

Honeycomb sandwich panel the most according to claim 1, it is characterised in that: the radius of described cylinder is the 1/4 ~ 1/2 of the described honeycomb grid length of side, and the thickness of described cylinder is 0.5 ~ 2 times of described honeycomb grid thickness.

Honeycomb sandwich panel the most according to claim 1 and 2, it is characterised in that: it is provided with the first draw-in groove inserted for the limit of described honeycomb grid in one end of described cylinder, the limit of described honeycomb grid is provided with the second draw-in groove inserted for described cylinder.

Honeycomb sandwich panel the most according to claim 1 and 2, it is characterised in that: described cylinder is made up of the arc plate being individually fixed in each honeycomb grid.

Honeycomb sandwich panel the most according to claim 1 and 2, it is characterised in that: described cylinder is one-body molded with described honeycomb grid.

Honeycomb sandwich panel the most according to claim 1, it is characterised in that: described top panel is surface plate or curved slab.

Honeycomb sandwich panel the most according to claim 1, it is characterised in that: described lower panel is surface plate or curved slab.