Reverse design device and method for partitioned periodic hierarchical structure considering material strength

Abstract

The invention provides a partition periodic hierarchical structure reverse design device and method considering material strength, and the device is characterized in that the device comprises a data input module which is used for inputting specified parameters; the data processing module is used for generating variables according to input specified parameters; the design variable optimization module is used for carrying out iterative optimization on the generated variables in combination with the collaborative optimization column formula to obtain the value of a macroscopic structure design variable and the value of a microstructure design variable; and the structure generation module is used for processing the obtained value of the macrostructure design variable and the value of the microstructure design variable to obtain partition periodic hierarchical structure data of a specified required structure. According to the partition periodic hierarchical structure reverse design device and method considering the material strength, the designed partition periodic hierarchical structure can meet the specified volume fraction requirement and the specified stress requirement.

Description

Technical Field

[0001] The present invention belongs to the field of structural design, and in particular relates to a device and method for reverse design of a partitioned periodic hierarchical structure taking material strength into consideration. Background Art

[0002] A large number of high-performance structures in nature, such as animal bones and plant rhizomes, often show different structural characteristics at different scales. Therefore, designing structural configurations at different length scales to obtain high-performance structures is considered to be one of the development directions of the next generation of lightweight structures. The inverse design method of partitioned periodic hierarchical structures is often based on topological optimization theory, with the required material volume, material mass, etc. as input, with the help of optimization algorithms, finite element analysis and other numerical methods, with macro configuration, micro structure configuration and distribution as optimization objects, iterative solution design to obtain partitioned periodic hierarchical structures.

[0003] The existing partitioned periodic hierarchical design model focuses on the maximum stiffness design under volume constraints. The local stress of the structure obtained by this method may exceed the material strength, affecting the safety and durability of the structure. The existing partitioned periodic hierarchical structure inverse design method considering material strength often specifies the initial distribution of the microstructure in advance through cluster analysis and other methods, and then performs the coordinated design of the macro-microstructure configuration. In the optimization design process, as the macro configuration changes, the optimal distribution of the microstructure will inevitably change. The method of specifying the microstructure distribution in advance limits the design space.

[0004] In summary, the existing inverse design methods of partitioned periodic hierarchical structures considering material strength cannot achieve the collaborative optimization design of partitioned multi-level macro-microstructures and microstructure distribution under strength constraints. Summary of the invention

[0005] The present invention is made to solve the above-mentioned problems, and its purpose is to provide a device and method for reverse design of partitioned periodic hierarchical structures taking into account material strength.

[0006] The present invention provides a partitioned periodic hierarchical structure inverse design device considering material strength, which is used to obtain the specified required structure according to the boundary and bearing capacity of the specified required structure, the initial value of the macrostructure design variable, the initial value of the microstructure design variable, the minimum value of the macrostructure and the microstructure design variable, the size of the macrostructure, the number of macrounits, the number of macrostructure design variables, the size of the microstructure, the number of microunits, the number of microstructure design variables, the number of types of microstructures, the volume fraction of each microstructure, the volume fraction of each microstructure occupying the macro design domain, the elastic modulus of the material and the strength of the material. The partitioned periodic hierarchical structure data has the following characteristics, including: a data input module, for users to input the boundary conditions and bearing capacity of the specified structure, the initial values ​​of the macro-design variables, the initial values ​​of the micro-structure design variables, the minimum values ​​of the macro-structure and micro-structure design variables, the size of the macro-structure, the number of macro-units, the number of macro-structure design variables, the size of the micro-structure, the number of micro-units, the number of micro-structure design variables, the number of types of micro-structures, the volume fraction of each micro-structure, the volume fraction of each micro-structure occupying the macro-design domain, the elastic modulus of the material and the strength of the material; a data processing module, for users to input the boundary conditions and bearing capacity of the specified structure, the initial values ​​of the macro-design variables, the initial values ​​of the micro-structure design variables, the minimum values ​​of the macro-structure and micro-structure design variables, the size of the macro-structure, the number of macro-units, the number of micro-structure design variables, the number of types of micro-structures, the volume fraction of each micro-structure, the volume fraction of each micro-structure occupying the macro-design domain, the elastic modulus of the material and the strength of the material; The periodic displacement matrix of the microstructure and the displacement vector of the macrostructure are calculated according to the boundary and bearing capacity of the specified required structure, the macro design variables, the micro structure design variables, the minimum values ​​of the macro structure and the micro structure design variables, the size of the macro structure, the number of macro units, the number of macro structure design variables, the size of the micro structure, the number of micro units, the number of micro structure design variables, the number of types of micro structures and the elastic modulus of the material; the design variable optimization module stores the collaborative optimization column formula, and updates the value of the macro structure design variable and the value of the micro structure design variable according to the periodic displacement matrix of the micro structure, the displacement vector of the macro structure, the strength of the material, the volume fraction of each micro structure, the volume fraction of each micro structure occupying the macro design domain and the collaborative optimization column formula; the iteration module stores the preset iteration termination condition, and is used to judge whether the iteration is completed according to the iteration termination condition and the value of the macro structure design variable and the value of the micro structure design variable. If so, the structure generation module is executed, and if not, the data processing module is executed; the structure generation module is used to process the updated value of the macro structure design variable and the value of the micro structure design variable to obtain the partition periodic hierarchical structure data of the specified required structure, wherein the expression of the collaborative optimization column formula is:

[0007]

[0008] In the formula represents the design variable of the ξ-th material of the ith macroelement, represents the design variable of the ξth material of the ith microunit, N M and N m denote the number of macro-structure and micro-structure design variables, respectively, NC represents the number of microstructure types, σ a is the strength of the material, K M represents the stiffness matrix of the macrostructure; represents the stiffness matrix of the ξ-th microstructure, χ ξ represents the periodic displacement matrix of the ξth microstructure, U M represents the displacement vector of the macrostructure, represents the test load matrix of the ξth microstructure, F M represents the load vector of the macrostructure, c is the correction factor updated with iteration, represents the P-norm stress of all microstructures in the multi-layer structure, is the objective function, g1 represents the volume constraint function of the macro configuration, g1(ρ)≤0 represents the volume constraint of the macro configuration, g2 represents the stress constraint function of the multi-level structure, represents the stress constraint of the multi-level structure, g3 represents the volume constraint function of the microstructure configuration, g3(γ)≤0 represents the volume constraint of the microstructure configuration, ρ min represents the minimum value of the macrostructure design variable, γ min It represents the minimum value of microstructure design variables. Macrostructure design variables include the design variables of all materials of all macro units. Microstructure design variables include the design variables of all micro units.

[0009] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein, in each iteration, the collaborative optimization formula updates the design variables through sensitivity, and the expression of the sensitivity of the objective function to the macro-structure design variables is: The expression of the sensitivity of the objective function to the microstructure design variables is: The expression of the sensitivity of the stress constraint function to the macrostructural design variables is: The expression of the sensitivity of the stress constraint function to the microstructure design variables is: Where ω=1,2,…,N r , T represents the transpose, λ represents the adjoint vector of the macro displacement vector, N D represents the number of columns of the adjoint matrix, P N Refers to P N Power.

[0010] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the P norm stress of all microstructures in the multi-level structure The expression is: Where P N Refers to P Npower, vm is the von Mises stress, represents the von Mises stress of the jth microelement at the i-th macroelement.

[0011] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the von Mises stress of the jth micro-unit at the i-th macro-unit is The expression is:

[0012] Where E0 is the elastic modulus of the material, q is the penalty parameter, is the von Mises stress of the jth microelement of the ξth microstructure at the ith macroelement.

[0013] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: the von Mises stress of the jth microunit of the ξth microstructure at the i-th macro unit is The expression is: Where T represents the transpose, V is the von Mises matrix, is the stress vector of the jth microunit of the ξth microstructure at the ith macrounit.

[0014] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the stress vector of the jth microunit of the ξth microstructure at the i-th macro unit is The expression is: In the formula is the equivalent uniform strain of the macro unit, D0 is the elastic matrix of the material, is the unit matrix, is the geometric matrix of the jth microcell, is the periodic displacement matrix of the ξ-th microstructure.

[0015] The partitioned periodic hierarchical structure reverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the expression of the correction factor is: Where c k represents the correction factor of the kth iteration, and δ represents the update period of the correction factor.

[0016] The present invention also provides a partitioned periodic hierarchical structure inverse design method considering material strength, which is used to obtain the partitioned periodic hierarchical structure data of the specified required structure according to the boundary and bearing capacity of the specified required structure, the initial values ​​of the macrostructure design variables, the initial values ​​of the microstructure design variables, the minimum values ​​of the macrostructure and the microstructure design variables, the size of the macrostructure, the number of macrounits, the number of macrostructure design variables, the number of microstructure design variables, the number of types of microstructures, the volume fraction of each microstructure, the volume fraction of each microstructure occupying the macrodesign domain, the elastic modulus of the material and the strength of the material, characterized in that: step S1, according to the boundary conditions and bearing capacity of the specified required structure, the macrostructure design variables, the microstructure design variables, the minimum values ​​of the macrostructure and the microstructure design variables, the size of the macrostructure, the number of macrounits, the macrostructure design variables The periodic displacement matrix of the microstructure and the displacement vector of the macrostructure are calculated according to the number of microstructures, the size of the microstructure, the number of microunits, the number of microstructure design variables, the number of types of microstructures and the elastic modulus of the material; step S2, according to the periodic displacement matrix of the microstructure, the displacement vector of the macrostructure, the strength of the material, the volume fraction of each microstructure, the volume fraction of each microstructure occupying the macro design domain and the collaborative optimization column formula, the value of the macrostructure design variable and the value of the microstructure design variable are updated; step S3, according to the iteration termination condition and the value of the macrostructure design variable and the value of the microstructure design variable, whether the iteration is completed is judged, if so, the structure generation module is executed, if not, the data processing module is executed; step S4, the updated value of the macrostructure design variable and the value of the microstructure design variable are processed to obtain the partition periodic hierarchical structure data of the specified required structure,

[0017] Among them, the expression of the collaborative optimization column is:

[0018]

[0019] In the formula represents the design variable of the ξ-th material of the ith macroelement, represents the design variable of the ξth material of the ith microunit, N M and N m denote the number of macro-structure and micro-structure design variables, respectively, N C represents the number of microstructure types, σ a is the strength of the material, K M represents the stiffness matrix of the macrostructure; represents the stiffness matrix of the ξ-th microstructure, χ ξ represents the periodic displacement matrix of the ξth microstructure, U M represents the displacement vector of the macrostructure, represents the test load matrix of the ξth microstructure, F Mrepresents the load vector of the macrostructure, c is the correction factor updated with iteration, represents the P-norm stress of all microstructures in the multi-layer structure, is the objective function, g1 represents the volume constraint function of the macro configuration, g1(ρ)≤0, represents the volume constraint of the macro structure configuration; g2 represents the stress constraint function of the multi-level structure, represents the stress constraint of the multi-level structure, g3 represents the volume constraint function of the microstructure configuration, g3(γ)≤0 represents the volume constraint of the microstructure configuration, ρ min represents the minimum value of the macrostructure design variable, γ min Represents the minimum value of microstructure design variables. Macrostructure design variables include the design variables of all materials of all macro units. The value of microstructure design variables includes the design variables of all micro units.

[0020] Functions and Effects of the Invention

[0021] According to the device and method for reverse design of partitioned periodic hierarchical structure considering material strength involved in the present invention, in the process of updating the value of design variables by using collaborative optimization formula, stress constraints and volume constraints participate together, and at the same time, the influence of material strength is considered in the collaborative optimization formula, and the partitioned multi-level structure finally designed satisfies both the specified volume fraction requirement and the specified stress requirement. Therefore, the device and method for reverse design of partitioned periodic hierarchical structure considering material strength involved in the present invention can realize the reverse design of partitioned multi-level structure that meets material strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a block diagram of a partitioned periodic hierarchical structure inverse design device considering material strength in an embodiment of the present invention;

[0023] Figure 2 is a unit cell diagram of a microstructure in an embodiment of the present invention;

[0024] Figure 3 is a unit cell distribution diagram of a multi-level structure in an embodiment of the present invention;

[0025] Figure 4 It is a partition periodic hierarchical structure shape diagram designed in an embodiment of the present invention;

[0026] Figure 5 is a force cloud diagram of the multi-level structure in an embodiment of the present invention;

[0027] Figure 6 It is a flow chart of a method for reverse design of a partitioned periodic hierarchical structure taking material strength into consideration in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and the accompanying drawings specifically illustrate the device and method for reverse design of partitioned periodic hierarchical structures taking into account material strength of the present invention.

[0029] In this embodiment, a partitioned periodic hierarchical structure inverse design device taking material strength into consideration is provided, which is used to obtain the partitioned periodic hierarchical structure data of the specified required structure according to the boundary conditions and bearing capacity of the specified required structure, the initial values ​​of the macro design variables, the initial values ​​of the micro structure design variables, the minimum values ​​of the macro structure and the micro structure design variables, the size of the macro structure, the number of macro units, the number of macro structure design variables, the size of the micro structure, the number of micro units, the number of micro structure design variables, the number of types of micro structures, the volume fraction of each micro structure, the volume fraction of each micro structure occupying the macro design domain, the elastic modulus of the material and the strength of the material.

[0030] In this embodiment, the boundary conditions of the required structure are specified as a cantilever beam, the required structural bearing capacity is 100 N, the initial value of the macro-design variable is 0.1, the initial value of the micro-structure design variable is 0.6, and the minimum value of the macro-structure and micro-structure design variables is 1×10 -6 , the size of the macrostructure is 120mm×50mm, the number of macrounits and the number of macrostructure design variables are 120×50, the size of the microstructure is 1mm×1mm, the number of microunits and the number of microstructure design variables are 30×30, the number of microstructure types is 4, there are 3 types of microstructures with a volume fraction of 60%, 1 type with a volume fraction of 100%, each microstructure occupies 10% of the volume fraction of the macro design domain, the elastic modulus of the material is 1GPa, and the strength of the material is 60MPa.

[0031] Figure 1 4 is a block diagram of a partitioned periodic hierarchical structure inverse design apparatus taking material strength into consideration in an embodiment of the present invention.

[0032] like Figure 1 As shown, the partitioned periodic hierarchical structure inverse design device 100 considering material strength of this embodiment includes a data input module 10, a data processing module 20, a design variable optimization module 30, an iteration module 40 and a structure generation module 50.

[0033] The data input module 10 is used for the user to input the boundaries and bearing capacity of the specified required structure, the initial values ​​of the macro-design variables, the initial values ​​of the micro-structure design variables, the minimum values ​​of the macro-structure and micro-structure design variables, the size of the macro-structure, the number of macro-units, the number of macro-structure design variables, the size of the micro-structure, the number of micro-units, the number of micro-structure design variables, the number of types of micro-structures, the volume fraction of each micro-structure, the volume fraction of each micro-structure occupying the macro-design domain, the elastic modulus of the material and the strength of the material.

[0034] The data processing module 20 is used to calculate the periodic displacement matrix of the microstructure and the displacement vector of the macrostructure according to the specified boundaries and bearing capacity of the required structure, macrostructure design variables, microstructure design variables, minimum values ​​of the macrostructure and microstructure design variables, the size of the macrostructure, the number of macrocells, the number of macrostructure design variables, the size of the microstructure, the number of microcells, the number of microstructure design variables, the number of types of microstructures and the elastic modulus of the material.

[0035] The design variable optimization module 30 stores a collaborative optimization formula, and updates the values ​​of the macrostructure design variables and the microstructure design variables according to the periodic displacement matrix of the microstructure, the displacement vector of the macrostructure, the strength of the material, the volume fraction of each microstructure, the volume fraction of each microstructure in the macro design domain and the collaborative optimization formula.

[0036] Among them, the expression of the collaborative optimization column is:

[0037]

[0038] In the formula represents the design variable of the ξ-th material of the ith macroelement, represents the design variable of the ξth material of the ith microunit, N M and N m denote the number of macro-structure and micro-structure design variables, respectively, N C represents the number of microstructure types, σ a is the strength of the material, K M represents the stiffness matrix of the macrostructure; represents the stiffness matrix of the ξ-th microstructure, χ ξ represents the periodic displacement matrix of the ξth microstructure, U M represents the displacement vector of the macrostructure, represents the test load matrix of the ξth microstructure, F M represents the load vector of the macrostructure, c is the correction factor updated with iteration, represents the P-norm stress of all microstructures in the multi-layer structure, is the objective function, g1 represents the volume constraint function of the macro configuration, g1(ρ)≤0 represents the volume constraint of the macro configuration, g2 represents the stress constraint function of the multi-level structure, represents the stress constraint of the multi-level structure, g3 represents the volume constraint function of the microstructure configuration, g3(γ)≤0 represents the volume constraint of the microstructure configuration, ρ min represents the minimum value of the macrostructure design variable, γ min Represents the minimum value of microstructure design variables. Macrostructure design variables include the design variables of all materials of all macro units. The value of microstructure design variables includes the design variables of all micro units.

[0039] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein, in each iteration, the collaborative optimization formula updates the design variables through sensitivity, and the expression of the sensitivity of the objective function to the macro-structure design variables is: The expression of the sensitivity of the objective function to the microstructure design variables is: The expression of the sensitivity of the stress constraint function to the macrostructural design variables is: The expression of the sensitivity of the stress constraint function to the microstructure design variables is: Where ω=1,2,…,N r , T represents the transpose, λ represents the adjoint vector of the macro displacement vector, N D represents the number of columns of the adjoint matrix, P N Refers to P N Power.

[0040] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the P norm stress of all microstructures in the multi-level structure The expression is: Where P N Refers to P N power, vm is the von Mises stress, represents the von Mises stress of the jth microelement at the i-th macroelement.

[0041] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the von Mises stress of the jth micro-unit at the i-th macro-unit is The expression is:

[0042] Where E0 is the elastic modulus of the material, q is the penalty parameter, is the von Mises stress of the jth microelement of the ξth microstructure at the ith macroelement.

[0043] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: the von Mises stress of the jth microunit of the ξth microstructure at the i-th macro unit is The expression is: Where T represents the transpose, V is the von Mises matrix, is the stress vector of the jth microunit of the ξth microstructure at the ith macrounit.

[0044] The partitioned periodic hierarchical structure inverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the stress vector of the jth microunit of the ξth microstructure at the i-th macro unit is The expression is: In the formula is the equivalent uniform strain of the macro unit, D0 is the elastic matrix of the material, is the unit matrix, is the geometric matrix of the jth microcell, is the periodic displacement matrix of the ξ-th microstructure.

[0045] The partitioned periodic hierarchical structure reverse design device considering material strength provided by the present invention may also have the following characteristics: wherein the expression of the correction factor is: Where c k represents the correction factor of the kth iteration, and δ represents the update period of the correction factor.

[0046] The iteration module 40 stores a preset iteration termination condition and is used to determine whether the iteration is completed based on the iteration termination condition and the values ​​of the macro-structure design variables and the values ​​of the micro-structure design variables. In this embodiment, if the difference between the values ​​of the macro-structure design variables and the values ​​of the micro-structure design variables obtained in this round of iteration and the values ​​of the macro-structure design variables and the values ​​of the micro-structure design variables obtained in the previous round of iteration is less than 0.01, the structure generation module 50 is executed; if the difference between the values ​​of the macro-structure design variables and the values ​​of the micro-structure design variables obtained in this round of iteration and the values ​​of the macro-structure design variables and the values ​​of the micro-structure design variables obtained in the previous round of iteration is greater than 0.01, the data processing module 20 is executed.

[0047] The structure generation module 50 is used to process the updated values ​​of the macro-structure design variables and the micro-structure design variables to obtain the partition periodic hierarchical structure data of the specified required structure. In this embodiment, the partition periodic hierarchical structure data includes the structure information of the required specified structure and the structure information of each microstructure.

[0048] Figure 2 1 is a unit cell diagram of the microstructure in an embodiment of the present invention.

[0049] like Figure 2 As shown, A, B, C and D are the structural information of four microstructures generated by collaborative optimization. The white part is the gap, that is, the area without material, and the non-white part is the area with material.

[0050] Figure 3 This is a unit cell distribution diagram of the multi-level structure in the embodiment of this experiment.

[0051] like Figure 3 As shown, the structural information of the required specified structure, i.e., the cantilever beam, includes the position distribution of the above four microstructures.

[0052] Figure 4 It is a partitioned periodic hierarchical structure shape diagram designed in an embodiment of the present invention.

[0053] like Figure 4 As shown, the structural information of the required specified structure, i.e., the cantilever beam, includes the microstructure, the microstructure is reasonably distributed, and the volume of the macrostructure and the porosity of the microstructure can be effectively controlled.

[0054] Figure 5 Graph showing the stress of the multi-layer structure in the embodiment of the present invention.

[0055] like Figure 5 It can be seen that the color bars from light to dark represent the stress of the multi-level structure from small to large, which shows that the maximum stress of the designed structure is below 60MPa. Therefore, the embodiment of the present invention can achieve the reverse design of the cantilever beam that meets the strength requirements under a given load.

[0056] The following describes, in conjunction with the accompanying drawings, a process of using a partitioned periodic hierarchical structure inverse design device 100 that takes material strength into consideration to perform a partitioned periodic hierarchical structure inverse design method that takes material strength into consideration.

[0057] Figure 6 It is a flow chart of a method for reverse design of a partitioned periodic hierarchical structure taking material strength into consideration in an embodiment of the present invention.

[0058] like Figure 6 As shown in FIG. 1 , the partitioned periodic hierarchical structure inverse design method considering material strength includes the following steps:

[0059] Step S1, using the data processing module 20 to calculate the periodic displacement matrix of the microstructure and the displacement vector of the macrostructure according to the boundary conditions and bearing capacity of the specified required structure, macro design variables, microstructure design variables, minimum values ​​of the macrostructure and microstructure design variables, the size of the macrostructure, the number of macro units, the number of macrostructure design variables, the size of the microstructure, the number of micro units, the number of microstructure design variables, the number of types of microstructures and the elastic modulus of the material.

[0060] Step S2, using the design variable optimization module 30 to update the values ​​of the macrostructure design variables and the microstructure design variables according to the periodic displacement matrix of the microstructure, the displacement vector of the macrostructure, the strength of the material, the volume fraction of each microstructure, the volume fraction of each microstructure occupying the macro design domain and the collaborative optimization column formula.

[0061] Step S3, using the iteration module 40 to determine whether the iteration is completed according to the iteration termination condition and the design variables, if so, executing the structure generation module 50, if not, executing the data processing module 20.

[0062] Step S4, using the structure generation module 50 to process the updated values ​​of the macro-structure design variables and the values ​​of the micro-structure design variables to obtain partition periodic hierarchical structure data of the specified required structure.

[0063] Functions and Effects of the Embodiments

[0064] According to the device and method for reverse design of partitioned periodic hierarchical structure considering material strength involved in the embodiment of the present invention, in the process of optimizing the design variables by using the collaborative optimization formula, stress constraints and volume constraints participate together, and at the same time, the influence of material strength is considered in the collaborative optimization formula, and the partitioned multi-level structure finally designed satisfies both the specified volume fraction requirement and the specified stress requirement. In short, the device and method for reverse design of partitioned periodic hierarchical structure considering material strength involved in the present invention can realize the reverse design of partitioned multi-level structure that meets material strength.

[0065] Furthermore, based on the asymptotic homogenization method to approximate the local stress of the microstructure, higher-precision stress can be obtained at a lower computational cost compared to the full-scale analysis method.

[0066] Furthermore, the present invention realizes the optimized design of macroscopic configuration and microstructural distribution based on the discrete material method, and realizes the coordinated optimized design of macroscopic and microscopic configuration and microstructural distribution by constructing a new stress interpolation function to describe the local stress.

[0067] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A partitioned periodic hierarchical structure inverse design device considering material strength, used for obtaining partitioned periodic hierarchical structure data of a specified required structure according to the boundary conditions and bearing capacity of the specified required structure, the initial values ​​of the macrostructure design variables, the initial values ​​of the microstructure design variables, the minimum values ​​of the macrostructure and the microstructure design variables, the size of the macrostructure, the number of macrounits, the number of macrostructure design variables, the size of the microstructure, the number of microunits, the number of microstructure design variables, the number of types of microstructures, the volume fraction of each microstructure, the volume fraction of each microstructure and solid material occupying the macro design domain, the elastic modulus of the material and the strength of the material, characterized in that: include: A data input module, used for the user to input the boundary conditions and bearing capacity of the specified structure, the initial values ​​of the macrostructure design variables, the initial values ​​of the microstructure design variables, the minimum values ​​of the macrostructure and microstructure design variables, the size of the macrostructure, the number of macrounits, the number of macrostructure design variables, the size of the microstructure, the number of microunits, the number of microstructure design variables, the number of types of microstructures, the volume fraction of each microstructure, the volume fraction of each microstructure occupying the macro design domain, the elastic modulus of the material, and the strength of the material; A data processing module, for calculating a periodic displacement matrix of the microstructure and a displacement vector of the macrostructure according to the boundary and bearing capacity of the specified required structure, the macrostructure design variables, the microstructure design variables, the minimum values ​​of the macrostructure and microstructure design variables, the size of the macrostructure, the number of the macrounits, the number of the macrostructure design variables, the size of the microstructure, the number of the microunits, the number of the microstructure design variables, the number of types of the microstructure and the elastic modulus of the material; A design variable optimization module stores a collaborative optimization formula, and updates the value of the macrostructure design variable and the value of the microstructure design variable according to the periodic displacement matrix of the microstructure, the displacement vector of the macrostructure, the strength of the material, the volume fraction of each microstructure, the volume fraction of each microstructure occupying the macro design domain and the collaborative optimization formula; An iteration module stores a preset iteration termination condition, and is used to determine whether the iteration is completed according to the iteration termination condition and the value of the macro-structure design variable and the value of the micro-structure design variable, and if so, execute the structure generation module, and if not, execute the data processing module; A structure generation module is used to process the updated values ​​of the macro-structure design variables and the micro-structure design variables to obtain partition periodic hierarchical structure data of the specified required structure. The expression of the collaborative optimization column formula is: In the formula represents the design variable of the ξ-th material of the ith macroelement, represents the design variable of the ξth material of the ith microunit, N M and N m denote the number of macro-structure and micro-structure design variables, respectively, N C represents the number of microstructure types, σ a is the strength of the material, K M represents the stiffness matrix of the macrostructure; represents the stiffness matrix of the ξ-th microstructure, χ ξ represents the periodic displacement matrix of the ξth microstructure, U M represents the displacement vector of the macrostructure, represents the test load matrix of the ξth microstructure, F M represents the load vector of the macrostructure, c is the correction factor updated with iteration, represents the P-norm stress of all microstructures in the multi-layer structure, is the objective function, g1 represents the volume constraint function of the macrostructure, g1(ρ)≤0 represents the volume constraint of the macrostructure; g2 represents the stress constraint function of the multi-level structure, represents the stress constraint of the multi-level structure, g3 represents the volume constraint function of the microstructure configuration, g3(γ)≤0 represents the volume constraint of the microstructure configuration, ρ min represents the minimum value of the macrostructure design variable, γ min represents the minimum value of the microstructure design variable, The macro-structure design variables include the design variables of all materials of all macro-units, and the values ​​of the micro-structure design variables include the design variables of all micro-units.

2. The device for reverse design of partitioned periodic hierarchical structures taking into account material strength according to claim 1, characterized in that: in, In each iteration, the collaborative optimization formula updates the design variables through the sensitivity, The expression of the sensitivity of the objective function to the macro-structural design variables is: The expression of the sensitivity of the objective function to the microstructure design variable is: The expression of the sensitivity of the stress constraint function to the macro-structural design variable is: The expression of the sensitivity of the stress constraint function to the microstructure design variable is: Where ω=1,2,…,N r , T represents the transpose, λ represents the adjoint vector of the macro displacement vector, N D represents the number of columns of the adjoint matrix, P N Refers to P N Power.

3. The device for reverse design of partitioned periodic hierarchical structure considering material strength according to claim 1, characterized in that: in, The P-norm stress of all microstructures in the multi-level structure The expression is: Where P N Refers to P N power, vm is the von Mises stress, represents the von Mises stress of the jth microelement at the i-th macroelement.

4. The device for reverse design of partitioned periodic hierarchical structures taking into account material strength according to claim 3, characterized in that: in, The von Mises stress of the jth micro-element at the i-th macro-element The expression is: Where E0 is the elastic modulus of the material, q is the penalty parameter, which ranges from 0 to 1. is the vonMises stress of the jth microelement of the ξth microstructure at the ith macroelement.

5. The device for reverse design of partitioned periodic hierarchical structure considering material strength according to claim 4, characterized in that: in, The von Mises stress of the jth microunit of the ξth microstructure at the i-th macrounit The expression is: Where T represents the transpose, v is the von Mises matrix, is the stress vector of the jth microunit of the ξth microstructure at the ith macrounit.

6. The device for reverse designing a partitioned periodic hierarchical structure taking into account material strength according to claim 5, characterized in that: in, The stress vector of the jth micro-element of the ξth microstructure at the i-th macro-element is The expression is: In the formula is the equivalent uniform strain of the macro unit, D0 is the elastic matrix of the material, I is the unit matrix, is the geometric matrix of the jth microcell, is the periodic displacement matrix of the ξ-th microstructure.

7. The device for reverse design of partitioned periodic hierarchical structures taking into account material strength according to claim 1, characterized in that: in, The expression of the correction factor is: Where c k represents the correction factor of the kth iteration, and δ represents the update period of the correction factor.

8. A partitioned periodic hierarchical structure inverse design method considering material strength, used to obtain partitioned periodic hierarchical structure data of a specified desired structure according to the boundary conditions and bearing capacity of the specified desired structure, the initial values ​​of the macrostructure design variables, the initial values ​​of the microstructure design variables, the minimum values ​​of the macrostructure and microstructure design variables, the size of the macrostructure, the number of macrocells, the number of macrostructure design variables, the size of the microstructure, the number of microcells, the number of microstructure design variables, the number of types of microstructures, the volume fraction of each microstructure, the volume fraction of each microstructure and solid material occupying the macro design domain, the elastic modulus of the material and the strength of the material, characterized in that: Step S1, calculating a periodic displacement matrix of the microstructure and a displacement vector of the macrostructure according to the boundary conditions and bearing capacity of the specified required structure, the macrostructure design variables, the microstructure design variables, the minimum values ​​of the macrostructure and microstructure design variables, the size of the macrostructure, the number of the macrounits, the number of the macrostructure design variables, the size of the microstructure, the number of the microunits, the number of the microstructure design variables, the number of types of the microstructure and the elastic modulus of the material; Step S2, updating the values ​​of the macrostructure design variables and the microstructure design variables according to the periodic displacement matrix of the microstructure, the displacement vector of the macrostructure, the strength of the material, the volume fraction of each microstructure, the volume fraction of each microstructure occupying the macro design domain and the collaborative optimization formula; Step S3, judging whether the iteration is completed according to the iteration termination condition and the value of the macro-structure design variable and the value of the micro-structure design variable, if so, executing the structure generation module, if not, executing the data processing module; Step S4, processing the updated values ​​of the macro-structure design variables and the values ​​of the micro-structure design variables to obtain partition periodic hierarchical structure data of the specified desired structure, The expression of the collaborative optimization column formula is: In the formula represents the design variable of the ξ-th material of the ith macroelement, represents the design variable of the ξth material of the ith microunit, N M and N m denote the number of macro-structure and micro-structure design variables, respectively, N C represents the number of microstructure types, σ a is the strength of the material, K M represents the stiffness matrix of the macrostructure; represents the stiffness matrix of the ξ-th microstructure, X ξ represents the periodic displacement matrix of the ξth microstructure, U M represents the displacement vector of the macrostructure, represents the test load matrix of the ξth microstructure, F M represents the load vector of the macrostructure, c is the correction factor updated with iteration, represents the P-norm stress of all microstructures in the multi-layer structure, is the objective function, g1 represents the volume constraint function of the macro configuration, g1(ρ)≤0, represents the volume constraint of the macro structure configuration, g2 represents the stress constraint function of the multi-level structure, represents the stress constraint of the multi-level structure, g3 represents the volume constraint function of the microstructure configuration, g3(γ)≤0 represents the volume constraint of the microstructure configuration, ρ min represents the minimum value of the macrostructure design variable, γ min Represents the minimum value of microstructure design variables. Macrostructure design variables include the design variables of all materials of all macro units. The value of microstructure design variables includes the design variables of all micro units.

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