Topology optimization of periodic structures using BESO based on unstructured design points

A topology optimization method is proposed for periodic structures when unit cells have different geometries and irregular FE meshes. The relationships between the elements and unstructured design points are established according to the Shepard interpolation functions. Then, the BESO method is applied by switching the density of the design points between solid and void iteratively until an optimized solution is achieved. Due to the separation of finite element analysis and design variables, the optimized topology of periodic structures can be clearly described by unstructured design points. Finally, numerical examples are presented to demonstrate the validity and effectiveness of the proposed heuristic method