35 results about "Topology optimization problem" patented technology

A design method of topology optimization for flexible hinge is disclosed in the invention, comprising following steps: step 1: establishing a design model of topology optimization for flexible hinge, setting an outline of flexible hinge with a typical notch as a shape of design domain and defining a rigid region (non-design domain); step 2: establishing a finite element model of topology optimization for flexible hinge; step 3: establishing a mathematical model of topology optimization problem for flexible hinge based on the finite element model; step 4: calculating a sensitivity of topology optimization problem for flexible hinge; step 5: employing an optimization algorithm to solve the topology optimization problem for flexible hinge, updating a design variable and obtaining a final topology result graph; step 6: according to the final topology result graph obtained by the topology optimization, extracting its outline and obtaining a novel flexible hinge by appropriate modification. Using the method of topology optimization, the invention designs the flexible hinge on a concept level. The novel flexible hinge can be designed with a more complex structure and more excellent performances, having a larger flexibility, a higher precision and a smaller maximum stress.

The invention provides an adaptive multi-step variable domain optimization method for automobile component solder joint layout based on topology optimization, Based on the finite element model of continuous solder joint element, the definition of multi-step variable domain solder joint topology optimization problem, the criteria of multi-step iteration progression and termination, and the verification of optimization scheme, the optimization design of structural solder joint number and layout form is completed. The technical proposal of the invention solves the problems that the existing solder joint topology optimization method in the prior art cannot simultaneously optimize the number of solder joints and the position of the solder joint arrangement, and the existing solder joint screening strategy will lead to the uncertainty of the design proposal. The technical proposal of the invention solves the problems that the existing solder joint topology optimization method cannot simultaneously optimize the number of solder joints and the position of the solder joint arrangement.

The invention discloses a continuum bi-material structure topology optimization method under displacement and global stress mixed constraints. The method comprises the steps of firstly, performing design variable description of a bi-material topology optimization problem according to a variable density method, setting two design variables for each unit, performing density filtering on the two design variables by applying a density filtering method to obtain two pseudo-densities corresponding to the unit, and on the basis of an epsilon stress relaxation method, proposing a bi-material stress relaxation method for constructing a stress constraint criterion of the unit; secondly, performing synthesis on stresses by utilizing a stress synthesis function to obtain a global stress constraint function, and solving the sensitivity of the global stress constraint function by applying an adjoint vector method and a composite function derivation rule; and finally, solving the optimization problemby applying a moving asymptote method, and performing iterative calculation until corresponding convergence conditions are met, thereby obtaining an optimal design scheme meeting the constraints. A bi-material topology structure meeting the displacement and global stress mixed constraint conditions can be obtained, and effective weight reduction can be realized.

A topology optimization method for a multi-degree-of-freedom compliant parallel mechanism, comprising steps in the following sequence: set the kinematic chain of the compliant parallel mechanism as the design domain of the topology optimization problem, establish the compliance matrix of each kinematic chain and assemble it into a compliant parallel mechanism According to the stiffness matrix of the mechanism, the stiffness and motion transfer relationship of the input and output points are derived, and a topology optimization model is established to optimize the kinematic chain. The method of the invention can be used to synthesize compliant parallel mechanisms such as 1 to 3 degrees of freedom in plane, 2 to 6 degrees of freedom in space, and redundant drive; without referring to the existing rigid mechanism, the topology with the best performance can be obtained according to the design problem, and the topology Unique and novel, it enriches the topology types of compliant parallel mechanisms.

The invention discloses a topology optimization method for isotropic materials based on second-order cone programming. The method takes Young's modulus E and Poisson's ratio v of isotropic materials as design variables, and performs singular value decomposition on the unit stiffness matrix. Construct a new decomposition representation of the stiffness matrix; and map the original design variables (E,v) to a new set of design variables (P,Q) through a bijective function, take (P,Q) as the design variables, and convert the original The topology optimization problem is transformed into a second-order cone programming problem, so as to obtain the global optimal (P, Q) solution, and obtain the corresponding optimal Young's modulus and Poisson's ratio through the bijective function; for any given target material category, the continuous solution is hierarchically clustered in (P,Q) space to obtain a high-fidelity discrete solution. By transforming the topology optimization problem of free isotropic materials into a second-order cone programming problem, the method of the invention can theoretically ensure the optimal solution of the problem and can obtain high-fidelity discrete solutions under any specified number of materials.

The invention discloses a macro-micro integrated structure topology optimization method considering stress constraints. According to the method, for the topology optimization problem of a structure with a macroscopic solid material and a micro-truss at the same time, the micro-truss is equivalently expressed as a mean material by adopting a representative volume element method; for the solid material, a stress comprehensive function is used for representing the stress level of the solid material; then an adjoint vector method is adopted for solving the stress comprehensive function and a partial derivative value of a displacement to a design variable; and finally, the macro-micro integrated structure topology optimization considering the stress constraint is solved by building a double-level optimization model, wherein an inner layer is solved by adopting a moving asymptotic line method, the displacement constraint of the structure and the stress constraint of the solid material are achieved, and an outer layer adopts a univariate function zero solving algorithm to realize the stress constraint of the micro-truss. The provided topology optimization method can effectively control the stress level of the macro-micro integrated structure to realize the topological optimization of the macro-micro integrated structure under the stress constraint.

The invention discloses a method for topology optimization of a bridge bracket structure under stress constraints. The method constructs a topology optimization model with the total volume of the bridge bracket structure as the target and the stress of the bridge bracket structure as a constraint, and is obtained by density filtering. The element density variable, using the solid isotropic microstructure / material model with a penalty factor combined with the finite element method to obtain the element node displacement; using the ε-relaxation method to obtain the stress constraint function of the element center point, and using the stress influence function method to calculate the element stress The constraint function is processed, and multiplied by the element volume to obtain the element stress constraint mixed function, and the sum of all element stress constraint mixed functions is used as the objective function of the topology optimization problem, and the topology optimization model under the stress constraint is obtained; the iterative calculation is performed until it satisfies Convergence conditions. The invention can greatly improve the solution efficiency of the stress-constrained topology optimization problem, and can effectively control the maximum stress of the bridge support arm structure.