Abstract: The topology optimization of cyclic-symmetry structures is studied by means of bi-directional evolutionary structural optimization (BESO) method. Due to the retention of non-uniform finite element discretization relative to one such type of structures, it is found that the sensitivity result depends upon the volume of the concerned finite element. As a result, different finite element discretizations will change the element removal/growth sequence in the BESO procedure. For this reason, a new concept of element sensitivity density is proposed to avoid the element-volume-dependence of the optimal design. Meanwhile, a new volume-weighted filtering technique is developed to control the checkerboard for the corresponding mesh. To verify the proposed method, a variety of numerical tests related to the concentrated load are studied in detail. Discussions show that the size effects of basic cells are important.

Key words: Cyclic-symmetry structure, Evolutionary structural optimization, Filtering technique, Sensitivity density, Size effect, Topology optimization