A design and manufacturing method of rudder wing based on high-toughness bionic microstructure

Abstract

The present invention discloses a method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure, specifically: establishing a mechanical constitutive model of a horseshoe crab shell core structure; using an initial three-dimensional network structure to equivalently replace the isotropic porous core in the horseshoe crab shell, and constructing a horseshoe crab shell-like porous sandwich structure; establishing a mathematical representation between the aspect ratio of the bionic core and the equivalent elastic modulus and equivalent stiffness; using the aspect ratio as a design variable, deformation capacity and impact toughness as optimization targets, using a simulation method to analyze the optimal aspect ratio range, and then designing the final three-dimensional network-like bionic core; using the number of skin layers of the horseshoe crab shell-like porous sandwich structure as an optimization target, designing a multi-layer skin structure, and coupling it with the three-dimensional network-like bionic core to form a high-toughness bionic microstructure, setting the high-toughness bionic microstructure into the shape of a rudder wing, and using 3D printing technology to prepare a physical object. The present invention improves the impact toughness of the rudder wing and reduces the mass of the rudder wing.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightweight functional structures. Background Art

[0002] Due to their lightweight and high load-bearing performance, advanced lightweight structures have received extensive attention in the fields of aerospace, vehicle engineering, etc. The complex topological structure features in natural biological structures are excellent sources of inspiration for obtaining the design of advanced lightweight structures. Among many biological structures, the defense organs of animals have extremely high impact resistance and energy dissipation efficiency, and are typical lightweight and high-toughness structures.

[0003] In these animal defense organs, there is generally a special structure: as a whole, it can be regarded as a sandwich core structure, which is jointly composed of two hard compact bones on both sides and a soft porous core structure in the center. The two compact bones on both sides can be regarded as parallel laminae, which can cooperate with the middle core to enhance toughness; the porous core bridges the compact bones and plays a role in regulating the system stiffness and improving the deformation ability. With the help of this complex porous sandwich core structure, the biological structure has super impact resistance.

[0004] In addition, no one has proposed how to apply the high-toughness structure of the horseshoe crab shell to the engineering field to improve the toughness of parts. At the same time, due to the complex microstructure features of multiple layers and pores in this bionic structure, when using existing equal-material and subtractive manufacturing technologies for manufacturing, this complex spatial structure needs to be disassembled into a large number of simple parts before processing, and reassembly is still required after processing, which will affect the strength, toughness, lightweight and manufacturing cycle of the structure; and existing equal-material and subtractive manufacturing technologies cannot solve the problems of complex processing technology (even unable to manufacture) and high cost when manufacturing complex spatial microstructures. Summary of the Invention

[0005] Object of the Invention: To solve the problems existing in the above-mentioned prior art, the present invention provides a method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure.

[0006] Technical Solution: The present invention provides a method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure, and the method includes the following steps:

[0007] Step 1: According to the mechanical constitutive model of the horseshoe crab shell, design a three-dimensional network structure as a bionic core to equivalently replace the porous core in the horseshoe crab shell;

[0008] Step 2: Use a simulation method to conduct toughening analysis and optimization design on the bionic core to obtain the optimal aspect ratio range of the bionic core;

[0009] Step 3: Set the top skin and the bottom skin, add another skin in the gap between the top and bottom skins, and couple the bionic core with the adjacent two layers of skins to obtain a multi-level high-toughness bionic microstructure;

[0010] Step 4: Set the high-toughness bionic microstructure obtained in Step 3 into the shape of a rudder wing;

[0011] Step 5: Finally, prepare a rudder wing based on the high-toughness bionic microstructure by combining with the 3D printing process.

[0012] Further, the horseshoe crab shell mechanical constitutive model in Step 1 is specifically:

[0013] E * =c h E h (l h / d h ) -i’

[0014] Among them, E * is the Young's modulus of the horseshoe crab shell core, c h is the shape factor of the horseshoe crab shell core structure, E h is the Young's modulus of the raw material of the horseshoe crab shell core, l h is the rod length, d h is the rod diameter, l h / d h is the aspect ratio of the horseshoe crab shell core.

[0015] Further, in Step 1, the regression analysis method is used to establish a three-dimensional network structure. The regression analysis method establishes a mathematical model between the aspect ratio l / d of the bionic core, the equivalent elastic modulus E, and the equivalent stiffness K. The form of the bionic core represented by this model is consistent with the mechanical model of the horseshoe crab shell structure. The specific model is as follows:

[0016]

[0017]

[0018] Among them, c i is a constant, l is the rod length of the bionic core, l / d is the aspect ratio of the bionic core, d is the rod diameter of the bionic core, and n is the polynomial order.

[0019] Further, in Step 2, the damage evolution model is used to simulate and analyze the plastic deformation ability and fracture toughness of the bionic core, so as to optimize the aspect ratio l / d of the bionic core and obtain the optimal aspect ratio l / d range.

[0020] Further, in Step 2, the optimal aspect ratio range of the bionic core is 5.8 - 8.4.

[0021] Furthermore, before 3D printing in step 4, powder discharge holes are added; after processing, annealing treatment and support removal treatment are carried out.

[0022] Beneficial effects: Referring to the high-toughness biological structural characteristics such as the horseshoe crab shell, the present invention designs a bionic core structure in which a three-dimensional network-shaped bridging core is coupled between multiple skins; toughening design is achieved by adjusting the aspect ratio of the bionic core structure; and it is prepared by laser additive manufacturing technology, reducing the complexity of preparation and simplifying the preparation process. The present invention improves the impact toughness of the rudder wing while reducing the mass of the rudder wing. The method disclosed by the present invention is applicable to the lightweight and toughening design and manufacturing of parts such as aircraft, automobiles, and pressure vessels. Description of the Drawings

[0023] Figure 1 It is the high-toughness porous sandwich structure in the horseshoe crab shell.

[0024] Figure 2 It is the three-dimensional network structure used to equivalently replace the horseshoe crab shell.

[0025] Figure 3 It is the three-dimensional network structure after aspect ratio optimization.

[0026] Figure 4 It is the multi-layer skin structure.

[0027] Figure 5 It is the toughened and optimized rudder wing and its powder discharge holes.

[0028] Figure 6 It is the microstructural core and multi-layer skin structure inside the optimized rudder wing. Detailed Embodiments

[0029] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0030] In the porous sandwich structure of the horseshoe crab shell, the core structure plays a role in regulating stiffness and providing a deformation space; through the porous core, the high-modulus skin can be regulated, thereby improving toughness. Based on the structural characteristics of the horseshoe crab shell, the Young's modulus of the porous core can be characterized by the formula E * = c h E h (l h / d h ) -i’ (E * is the Young's modulus of the horseshoe crab shell core, c h is the shape factor of the core structure, E h is the Young's modulus of the raw material of the horseshoe crab shell core, l his the rod length, d h is the rod diameter, l h / d h is the aspect ratio of the horseshoe crab shell core, and i' is the order of the polynomial). Among them, E h is the inherent property of the material, c h is related to the geometric structure of the core; i'≥2. In the compression (tension)-dominant biological microstructure, i' = 2; in the bending-dominant structure, i' = 4; and the rest are between the two.

[0031] Since c h has a much lower impact on E * than (l h / d h ), -i’ therefore, in the horseshoe crab shell biological structure, the mechanical properties of the core microstructure mainly depend on the aspect ratio. Inspired by this, the present invention proposes to equivalently replace the irregular porous core in the horseshoe crab shell with a three-dimensional network structure to improve the manufacturability, stability, and overall mechanical properties of the bionic structure; constructs a design method for the bionic horseshoe crab shell porous sandwich structure to regulate the mechanical properties through the aspect ratio; and adopts the strategy of increasing the number of skins to further improve the toughness of the rudder wing.

[0032] This implementation first extracts the structural characteristics of the horseshoe crab shell, then constructs a bionic core microstructure to equivalently replace the irregular horseshoe crab shell core, and then realizes the toughening design of the bionic microstructure by changing the aspect ratio of the bionic core, and finally further improves the toughness of the microstructure by adding skins, specifically as follows:

[0033] Step 1: Based on the structural characteristics of the horseshoe crab shell, extract a high-toughness porous sandwich structure (as Figure 1 shown), and construct a mechanical constitutive model of the porous core structure, the expression of which is:

[0034] E * = c h E h (l h / d h ) -i

[0035] In the formula, E * is the Young's modulus of the horseshoe crab shell core, c h is the shape factor of the core structure, E h is the Young's modulus of the raw material of the horseshoe crab shell core, l h / d h is the aspect ratio of the horseshoe crab shell core microstructure, and i' is the order of the polynomial.

[0036] Step 2: Design an initial three-dimensional network structure as the bionic core structure to equivalently replace the irregular isotropic porous core in the horseshoe crab shell, as Figure 2As shown. (In this embodiment, the bionic structure is applied to the manufacture of the rudder wing. Figure 2 Connected to the three-dimensional network structure are the upper and lower skins. The two skins and the bionic core form a bionic structure, and these two skins are applied to the rudder wing as the two skins of the rudder wing).

[0037] Step 3: For the porous core (bionic core structure) of the bionic sandwich structure, the present invention uses the regression analysis method to propose and establish a mathematical model between the aspect ratio l / d of the three-dimensional network structure, the equivalent elastic modulus E, and the equivalent stiffness K. The form of the bionic core represented by this model is consistent with the mechanical model of the horseshoe crab shell structure, and its mathematical relationship satisfies:

[0038]

[0039] where c i is a constant, l is the rod length of the three-dimensional network bionic core structure, l / d is the aspect ratio of the bionic core structure, and n is the polynomial order.

[0040] Step 4: Combining the finite element simulation method, a damage evolution model is used to simulate and analyze the plastic deformation ability and fracture toughness of the designed horseshoe crab shell sandwich structure. Taking the aspect ratio as the design variable and the deformation ability and impact toughness as the optimization objectives, the optimal aspect ratio range is analyzed, and the aspect ratio l / d of the core is optimized (as Figure 3 shown), and the optimal aspect ratio l / d range is obtained.

[0041] The optimization results show that when the value range of l / d is 5.8 - 8.4, this structure exhibits excellent toughening effects.

[0042] Step 5: On the basis of the horseshoe crab shell porous sandwich structure, multiple skins are added. The specific structure of adding multiple skins is: another skin is set in the middle of the bionic structure, and the skin is coupled with the bionic core to obtain a multi-level high-toughness bionic microstructure, as Figure 4 shown;

[0043] Step 6: The high-toughness bionic microstructure is made into the shape of a rudder wing, and the toughening design and optimization of the rudder wing are carried out, as Figure 5 and Figure 6 ; then it is manufactured in combination with the 3D printing process, and pre-treatment and post-treatment processes are performed during the processing, and then a high-toughness porous sandwich structure or a bionic rudder wing is manufactured.

[0044] The pre-treatment process is to add powder discharge holes before 3D printing processing; the post-treatment process is to perform annealing treatment and support removal treatment after processing is completed.

[0045] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure, characterized in that: The specific steps include: Step 1: Based on the mechanical constitutive model of horseshoe crab shell, a three-dimensional network structure is designed as a bionic core to replace the porous core in the horseshoe crab shell; Step 2: using a simulation method to perform toughening analysis and optimization design on the bionic core to obtain an optimal aspect ratio range of the bionic core; the simulation method uses finite element simulation; Step 3: Setting a top skin and a bottom skin, adding another skin in the gap between the top skin and the bottom skin, coupling the bionic core with the two adjacent skin layers, and obtaining a multi-level high-toughness bionic microstructure; Step 4: setting the high-toughness bionic microstructure of step 3 into the shape of a rudder wing; Step 5: Combined with the 3D printing process, a rudder wing based on a high-toughness bionic microstructure is finally prepared; The step 1 uses a regression analysis method to establish a three-dimensional network structure. The regression analysis method establishes a mathematical model between the aspect ratio l / d of the bionic core and the equivalent elastic modulus E and the equivalent stiffness K. The bionic core represented by the model is consistent with the form of the horseshoe crab shell mechanical model. The model is specifically as follows: Among them, c i is a constant, l is the rod length of the bionic core, l / d is the aspect ratio of the bionic core, d is the rod diameter of the bionic core, and n is the polynomial order.

2. The method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure according to claim 1, characterized in that: The mechanical constitutive model of horseshoe crab shell in step 1 is specifically: AND * =c h AND h (the h / d h ) -i’ Among them, E * is the Young's modulus of the horseshoe crab shell core, c h is the shape factor of the core structure of the horseshoe crab shell, E h is the Young's modulus of the raw material of the horseshoe crab shell core, l h is the rod length, d h is the rod diameter, l h / d h is the aspect ratio of the core of the horseshoe crab shell, and i' is the order of the polynomial.

3. The method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure according to claim 1, characterized in that: The step 2 uses a damage evolution model to simulate and analyze the plastic deformation capacity and fracture toughness of the bionic core, thereby optimizing the aspect ratio l / d of the bionic core and obtaining the value range of the optimal aspect ratio l / d.

4. The method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure according to claim 1 is characterized in that: In step 2, the optimal aspect ratio of the bionic core is in the range of 5.8 to 8.

4.

5. The method for designing and manufacturing a rudder wing based on a high-toughness bionic microstructure according to claim 1, characterized in that: In step 4, before the 3D printing process, a powder discharge hole is added; after the process is completed, an annealing heat treatment and a support removal process are performed.

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