Method for topological optimization of multiphase material flexible mechanisms under stress constraints

Abstract

The invention belongs to related technical field of optimum structural design, discloses a method for topological optimization of multiphase material flexible mechanisms under stress constraints, and aims at optimizing structures of the multiphase material flexible mechanisms. The method comprises the following steps of: (1) constructing a multiphase material level set topological description model to describe distribution of a multiphase material structure; (2) constructing a rigidity interpolation model and a separable stress interpolation model to respectively calculate elastic rigidity and stress of the multiphase material structure; and (3) constructing a weighing method and stress punishment-based multiphase material flexible mechanism parameterized level set topological optimization model, optimizing output displacement and flexibility of a flexible mechanism, and controlling local stress of the multiphase material structure. The method is applied to topological optimization design of multiphase material flexible mechanisms under stress constraints, the optimized multiphase material flexible mechanisms have the advantages of being high in flexibility and high in rigidity, flexible knot parts of the multiphase material flexible mechanisms do not have single point hinge phenomenon, the structural strength requirements are satisfied, and the stress concentration problems are eased.

Description

technical field [0001] The invention belongs to the related technical field of structural optimization design, and more specifically, relates to a topology optimization method of a multiphase material flexible mechanism under stress constraints. Background technique [0002] A flexible mechanism is a mechanical mechanism that transmits force, displacement and energy through the deformation of a flexible member. Flexible mechanisms are mainly divided into two categories: centralized flexible mechanisms and distributed flexible mechanisms. The centralized flexible mechanism is only flexible in part of the whole mechanism, and the motion is transmitted through the flexible joint instead of the kinematic pair in the traditional mechanism, and the rest is still a rigid body component; the distributed flexible mechanism distributes the deformation in the entire structure, and any part of the structure Both contribute to the flexibility and output of the distributed flexible mecha...

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Problems solved by technology

However, the existing two types of structural topology optimization methods based on stress constraints have their own shortcomings: the local stress method needs to optimize the stress of each unit in the design domain, that is, a stress constraint needs to be added to each unit in the design domain, although it can Accurately control the local stress of the structure, but it leads to a large number of constraints and expensive calculation costs, and the calculation efficiency is low; the global stress method uses a stress evaluation function to define the overall stress of the structure (such as the maximum stress of the structure), although it can obtain a relatively High computational efficiency, but cannot control local stresses, and can cause optimization instability and parameter dependence

However, there is still no method to simultaneously consider multiphase materials and stress constraints in the design of flexible mechanisms

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