Minimum length scale control in structural topology optimization based on the Moving Morphable Components (MMC) approach

A novel approach, which can control the minimum length scale in topology optimization in a straightforward and explicit way, is proposed in the present paper. This approach is constructed under the so-called Moving Morphable Components (MMC) based solution framework where optimized structural topology can be found by changing the shapes and layout of a set of trapezoid-shaped structural components on a fixed finite element mesh. The eXtended Finite Element Method (XFEM) is employed for structural response analysis and shape sensitivity information is obtained by carrying out numerical integration along the structural boundary. A precision definition of the minimum length scale of a structure is also suggested based on the proposed solution framework. Compared with existing approaches, the proposed approach can achieve minimum length scale control by simply setting lower bounds on a set of geometric design variables. Only a small number of purely geometric constraints imposed on the sizes of intersection regions should be considered explicitly in order to get a complete minimum length scale control. Numerical examples demonstrate the effectiveness of the proposed method.