A checkerboard-free topology map extraction method for compliant mechanisms

Abstract

The invention discloses a method for extracting a no-checkerboard topological diagram from a compliant mechanism. The method comprises the following steps of: establishing a compliant mechanism topology optimization model with volume constraints; carrying out checkerboard analysis on the topological diagram, and establishing constraint conditions for checkerboard eliminating based on the basis; establishing optimum updating rules with design variables for checkerboard eliminating; and processing until the no-checkerboard topological diagram is extracted from the compliant mechanism. The method for extracting the no-checkerboard topological diagram from the compliant mechanism has the advantages that the problem of checkerboard caused during SIMP (Solid Isotropic Material with Penalization)-method-based design variable relaxation can be effectively solved, and then, the no-checkerboard topological diagram is extracted from the compliant mechanism; unit density in a design domain is not required for being smoothened, so that the intermediate unit phenomenon in topology optimization results can be greatly improved; and the constraint conditions for checkerboard eliminating are only applied between a lower-density unit in a checkerboard area and a unit, with the density higher than or equal to a given threshold, in a neighbor area of the checkerboard area, so that the computational complexity is low.

Description

technical field [0001] The invention relates to the technical field of topology map extraction in the topology optimization design of a compliant mechanism, in particular to a method for extracting a checkerboard-free topological map of a compliant mechanism. Background technique [0002] With the rapid development of microelectromechanical systems, micromachining and micromanipulation, and new materials, the design of compliant mechanisms has become a research hotspot in the field of mechanism science at home and abroad. [0003] Using the topology optimization method to study the design of the compliant mechanism only needs to give the design domain and specify the input and output positions, and does not need to start from a known rigid mechanism, and the obtained mechanism has the superior performance of distributed flexibility, which has attracted great attention. . This method is usually based on finite element analysis. In the initial stage of topology optimization, ...

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Problems solved by technology

The essence of the method of imposing geometric constraints is to smooth the cell density, so it has a good effect of eliminating the checkerboard, but it is easy to cause the problem of intermediate cells

[0007] After that, the method based on wavelet, the method of combining uncoordinated elements and hybrid elements, the method of combining topology analysis and stress analysis, and the method based on topological description functions have been developed successively. These methods also have a certain ability to eliminate checkerboard. effect, but since they still need to smooth the element density, they cannot avoid the appearance of intermediate elements

[0008] The topology optimization method based on level set is also an effective method to solve the checkerboard problem, but this method also has defects such as initial sensitivity, inability to generate new holes, low computational efficiency, and difficulty in converging to rough corners. Propose some improved methods, but these problems have not been fully solved

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