CN113821889B - Screen piece bionic design method based on pigeon wing structural characteristics - Google Patents

Abstract

The invention discloses a bionic design method for a sieve plate based on the structural characteristics of pigeon wings, which includes the following steps: the first step is to select the right wing of the pigeon as a biological model, and use reverse engineering technology to obtain its three-dimensional numerical model; the second step is to: Establish a three-dimensional rectangular coordinate system for the pigeon's right wing; the third step is to extract the wing structure parameters based on the solid model of the pigeon's right wing established in the first step and optimize the wing structure. The present invention provides a bionic design method for sieve plates based on the structural characteristics of pigeon wings. The wing-shaped structure of the sieve plates reduces the overall pressure difference in the crushing chamber, which is conducive to timely sieving of materials, and at the same time, violent vortices are generated in the air flow field. The movement destroys the original relatively regular movement trajectory of the circulation layer and produces a movement that is conducive to the material coming out of the screen. In addition, this violent vortex motion continuously consumes energy and increases the relative speed between the material and the hammer, allowing it to be destroyed and crushed faster.

Description

A bionic design method for screen plates based on the structural characteristics of pigeon wings

Technical field

The invention belongs to the technical field of crusher screen design and manufacturing, and specifically relates to a screen bionic design method based on the structural characteristics of pigeon wings.

Background technique

Crushing is one of the indispensable and important processes in feed processing. The performance of the crusher directly affects the economic benefits of the enterprise and the quality of the feed. The hammer crusher has strong applicability to raw materials, simple structure, and easy operation. It is widely used in the feed processing industry due to its advantages.

The screen is the core component of the hammer mill. When the hammer mill is running, a material circulation layer will be generated on the inner wall of the screen, seriously reducing the efficiency of the hammer mill.

During the flight, pigeons spread their wings and can destroy the local air flow field. The movement trajectory is very similar to the sieve plate that destroys the material circulation layer. Therefore, it is becoming more and more important to improve the ability of the screen to destroy the material circulation layer through bionic design of the pigeon's wing structure.

Contents of the invention

The purpose of the present invention is to solve the above problems and provide a bionic design method of sieve plates based on the structural characteristics of pigeon wings that can improve the screening efficiency of the crusher.

In order to solve the above technical problems, the technical solution of the present invention is: a screen bionic design method based on the structural characteristics of domestic pigeon wings, including the following steps:

S1. Select the right wing of the domestic pigeon as the biological model, and use reverse engineering technology to obtain its three-dimensional numerical model;

S2. Establish the three-dimensional rectangular coordinate system of the pigeon's right wing;

S3. Extract the wing structure parameters according to the solid model of the pigeon's right wing established in step S1, and optimize the wing structure.

Further, step S3 also includes the following sub-steps:

S31. Using the Y-Z plane in the three-dimensional direct coordinate system in step S2, uniformly intercept the wing structure along the direction from the wing root to the wing tip, and obtain 7 profile curves at different positions;

S32. Optimize the curve obtained in step S31 through curvature sampling, reduce the number of points in the smooth area to reduce the difficulty of fitting, and retain the number of points in the high curvature area to retain more details;

S33. Analyze 7 sets of curves, discard inappropriate curves, and finally select the 2nd, 3rd, and 4th sets of curves;

S34. Establish a curve coordinate system and extract 200 to 300 points on the curve;

S35. Use the least squares method to fit the upper curve obtained in S34 to obtain the upper curve characteristic equation.

S36. Compare the obtained 2, 3, and 4 sets of curves. Compared with the other curves, the 2nd set of curves has the greatest protrusion and the largest impact area on the material. Finally, the 2nd set of curves is selected as the final curve;

S37. Obtain the wing shape parameters based on the characteristic curve in S34;

S38. Combined with the structure of the crushing chamber and considering the convenience and cost of processing, the screen is divided into 6 equal parts along the circumferential direction and 6 sets of wing-shaped structures are designed;

S39. According to the design specification principles of the wing, select three parameters such as the maximum relative camber f of the airfoil, the relative position of the maximum camber x _f , and the relative position of the maximum thickness x _t to optimize the airfoil, and set the optimization range of the three parameters. A corresponding response surface experimental design plan was designed to further optimize the parameters.

Furthermore, the design response surface test plan described in step S39 further optimizes the parameters of the bionic structure, specifically using the maximum relative curvature f, the maximum relative position of the curvature x _f , and the maximum thickness relative position x _t as independent variables, and crushing the indoor pressure The difference is the performance evaluation index, and a response surface test plan based on Box-Behnken is designed; finite element analysis software is used to verify the response surface test plan and determine the best bionic parameter combination.

Further, the three-dimensional rectangular coordinate system in step S2 is as follows: the wing root-wing tip direction is the X-axis, the upper wing surface-lower wing surface direction is the Y-axis, and the wing flight feather-wing compound feather direction is the Z axis. The three-dimensional rectangular coordinate system established.

Furthermore, when reverse engineering is used in step S1, a handheld 3D scanner is used to conduct non-contact scanning of pigeon wings to obtain point cloud data, and the reverse engineering software Geomagic Studio is used to simplify and reduce noise in the point cloud data. Preprocessing, encapsulation processing, improving the triangular patch polygon model, constructing NURBS surfaces, and completing the reverse reconstruction of the three-dimensional solid model.

Further, in step S34, the contour curve is imported into Getdata software to extract coordinate points.

Further, in step S35, Origin software is used to fit the contour curve to obtain the curve characteristic equation.

Further, in the S39, the maximum relative curvature is 7% to 11%, the maximum curvature is 40% to 60% relative to the position, and the maximum thickness is 10% to 20% relative to the position.

The beneficial effects of the present invention are: the invention provides a bionic design method of sieve plates based on the structural characteristics of pigeon wings. The wing-shaped structure of the sieve plates reduces the overall pressure difference in the crushing chamber, which is conducive to timely sieving of materials, and at the same time, the air flow Violent vortex motion is generated in the field, which destroys the original relatively regular movement trajectory of the circulation layer and produces a movement that is conducive to the material coming out of the screen. In addition, this violent vortex motion continuously consumes energy and increases the relative speed between the material and the hammer, allowing it to be destroyed and crushed faster.

Description of the drawings

Figure 1 is a step diagram of a screen bionic design method based on the structural characteristics of pigeon wings according to the present invention;

Figure 2 is a schematic diagram comparing the structure and characteristic curves of pigeon wings according to the present invention;

Figure 3 is a schematic diagram of the screen structure of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

As shown in Figures 1 to 3, the present invention provides a screen bionic design method based on the structural characteristics of pigeon wings, which is characterized by including the following steps:

S1. Select the right wing of the domestic pigeon as the biological model, and use reverse engineering technology to obtain its three-dimensional numerical model.

When reverse engineering is used in step S1, a handheld 3D scanner is used to conduct non-contact scanning of pigeon wings to obtain point cloud data. The reverse engineering software Geomagic Studio is used to sequentially perform preprocessing such as simplification and noise reduction on the point cloud data. Encapsulation processing, improving the triangular patch polygon model, constructing NURBS surfaces, and completing the reverse reconstruction of the three-dimensional solid model.

In this embodiment, the right wing of a domestic pigeon is used as a biological model, and a handheld three-dimensional scanner is used to conduct non-contact scanning of the wings to obtain point cloud data. The reverse engineering software Geomagic Studio is used to simplify and reduce the point cloud data in sequence. Noise preprocessing, encapsulation processing, improving the triangular patch polygon model, constructing NURBS surfaces and other operations completed the reverse reconstruction of the maxillary solid model. Perform fitting accuracy determination analysis and model adjustment to meet feature extraction requirements. Among them, reverse engineering technology is an existing technology and is adopted in this embodiment to achieve specific functions.

S2. Establish the three-dimensional rectangular coordinate system of the pigeon's right wing.

The three-dimensional rectangular coordinate system in this step is: a three-dimensional rectangular coordinate established with the wing root-wing tip direction as the X-axis, the upper wing surface-lower wing surface direction as the Y-axis, and the wing flight feather-wing compound feather direction as the Z axis. Tie. Specifically, the structural parameters of the wings are extracted to optimize the sawtooth structure. The three-dimensional right angle established with the wing root-wing tip direction as the X-axis, the upper wing surface-lower wing surface direction as the Y-axis, and the wing flight feather-wing compound feather direction as the Z-axis. The coordinate system is as shown in Figure 2. Use the Y-Z plane to uniformly intercept the wing profile to form a side profile. Select the applicable curve, import the profile into the Getdata software, extract 200 points on the curve, and then use the Origin software to simulate the upper curve. Combined, the characteristic equation of the curve is obtained.

S3. Extract the wing structure parameters according to the solid model of the pigeon's right wing established in step S1, and optimize the wing structure.

Step S3 also includes the following sub-steps:

S31. Use the Y-Z plane in the three-dimensional direct coordinate system in step S2 to uniformly intercept the wing structure along the direction from the wing root to the wing tip, and obtain 7 profile curves at different positions.

S32. Optimize the curve obtained in step S31 through curvature sampling, reduce the number of points in the smooth area to reduce the difficulty of fitting, and retain the number of points in the high curvature area to retain more details.

S33. Analyze 7 sets of curves, discard inappropriate curves, and finally select the 2nd, 3rd, and 4th sets of curves.

S34. Establish a curve coordinate system and extract 200 to 300 points on the curve.

In step S34, the method for extracting points on the curve is to import the contour curve into the Getdata software to extract coordinate points.

S35. Use the least squares method to fit the upper curve obtained in S34 to obtain the upper curve characteristic equation.

In the step S35, Origin software is used to fit the contour curve to obtain the curve characteristic equation.

S36. Compare the obtained 2, 3, and 4 sets of curves. Compared with the other curves, the 2nd set of curves has the greatest protrusion and the largest impact area on the material. Finally, the 2nd set of curves is selected as the final curve.

S37. Obtain the wing shape parameters based on the characteristic curve in S34.

S38. Combined with the structure of the crushing chamber and considering the convenience and cost of processing, the screen is divided into 6 equal parts along the circumferential direction and 6 sets of wing-shaped structures are designed.

S39. According to the design specification principles of the wing, select three parameters such as the maximum relative camber f of the airfoil, the relative position of the maximum camber x _f , and the relative position of the maximum thickness x _t to optimize the airfoil, and set the optimization range of the three parameters. A corresponding response surface experimental design plan was designed to further optimize the parameters.

In step S39, a response surface test plan is designed to further optimize the parameters of the bionic structure. Specifically, the maximum relative curvature f, the relative position of the maximum curvature x _f , and the relative position of the maximum thickness x _t are used as independent variables, and the pressure difference in the crushing chamber is used as the performance evaluation. Index, design a response surface test plan based on Box-Behnken; use finite element analysis software to verify the response surface test plan and determine the best bionic parameter combination.

In step S39, the maximum relative curvature is 7% to 11%, the relative position of the maximum curvature is 40% to 60%, and the relative position of the maximum thickness is 10% to 20%.

Based on the bionic design and screen design principles, the parameters in steps S2, S3, and S4 are reasonably set, and the response surface test plan is designed to optimize the screen structure and combine the bionic design criteria and screen design principles.

Those of ordinary skill in the art will appreciate that the embodiments described here are provided to help readers understand the principles of the present invention, and it should be understood that the scope of the present invention is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific modifications and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and these modifications and combinations are still within the protection scope of the present invention.

Claims (1)

1. A sieve plate bionic design method based on pigeon wing structural features is characterized by comprising the following steps:

s1, selecting a pigeon right wing as a biological model, and obtaining a three-dimensional value model by adopting a reverse engineering technology;

s2, establishing a three-dimensional rectangular coordinate system of the right wing of the pigeon;

s3, extracting wing structure parameters according to the entity model of the right wing of the pigeon established in the step S1, and optimizing the wing structure;

the step S3 further comprises the sub-steps of:

s31, uniformly intercepting the wing structure along the direction from the wing root to the wing tip by utilizing the Y-Z plane in the three-dimensional direct coordinate system in the step S2 to obtain 7 section curves at different positions;

s32, optimizing the curve obtained in the step S31 through curvature sampling, reducing the number of points in a smooth area, reducing fitting difficulty, and reserving the number of points in a high curvature area so as to reserve more details;

s33, analyzing the 7 groups of curves, discarding unsuitable curves, and finally selecting the 2 nd, 3 rd and 4 th groups of curves;

s34, establishing a curve coordinate system, and extracting 200 to 300 points on the curve;

s35, fitting the upper curve obtained in the S34 by adopting a least square method to obtain an upper curve characteristic equation;

s36, comparing the obtained 2, 3 and 4 groups of curves, wherein compared with the rest curves, the 2 nd group of curves have the greatest protrusion degree and the greatest striking area for the material, and finally selecting the 2 nd group of curves as the final curve;

s37, obtaining wing-shaped shape parameters based on the characteristic curve in the S34;

s38, combining the structure of the crushing chamber, equally dividing the sieve sheet into 6 parts along the circumferential direction in consideration of the convenience and cost of processing, and designing 6 groups of wing-shaped structures;

s39, selecting the maximum relative camber f and the maximum camber relative position x of the wing according to the design rule of the wing _f Relative position x of maximum thickness _t 3 parameters are optimized for the wing shape, 3 parameter optimization ranges are set, and corresponding response surface test design schemes are designed for further optimizing the parameters;

the design response surface test scheme in step S39 further optimizes parameters of the bionic structure, specifically, the maximum relative bending degree f and the maximum bending degree relative position x _f Maximum thickness relative position x _t Independent variables, namely, taking the pressure difference in the crushing chamber as an efficiency evaluation index, and designing a response surface test scheme based on Box-Behnken; verifying the response surface test scheme by using finite element analysis software, and determining the optimal bionic parameter combination;

the three-dimensional rectangular coordinate system in the step S2 is a three-dimensional rectangular coordinate system established by taking the wing root-wing tip direction as an X axis, the upper wing surface-lower wing surface direction as a Y axis and the wing flying feather-wing re-feather direction as a Z axis; extracting a structural parameter optimization sawtooth structure of a wing, taking the wing root-wing tip direction as an X axis, taking the upper wing surface-lower wing surface direction as a Y axis, taking the wing flying feather-wing compound feather direction as a three-dimensional rectangular coordinate system established by a Z axis, uniformly intercepting a wing section by using a Y-Z plane to form a side profile, selecting an applicable curve, importing the profile into Getdata software, extracting 200 points on the curve, and then fitting the upper curve by using Origin software to obtain a curve characteristic equation;

when reverse engineering is adopted in the step S1, non-contact scanning is carried out on pigeon wings by utilizing handheld 3D scanning to obtain point cloud data, and reverse engineering software Geomagic Studio is used for simplifying, reducing noise, preprocessing, packaging, perfecting a triangular patch polygonal model, constructing a NURBS curved surface and completing reverse reconstruction of a three-dimensional entity model;

in the step S34, the contour curve is imported into the Getdata software to extract coordinate points;

in the step S35, the contour curve is fitted by using Origin software to obtain a curve characteristic equation;

the maximum relative bending degree in the S39 is 7% -11%, the maximum bending degree relative position is 40% -60%, and the maximum thickness relative position is 10% -20%.