A New Study on Mesh Dependency of Plate Topology Optimization under Uniform Pressure

The mesh dependency of plate topology optimization under uniform pressure is investigated. The plate is modelled as a three-dimensional (3D) solid structure now. Along the thickness multiple layer meshes are employed and the number of layers is different for different meshing cases. In finite element model (FEM), load is applied on nodes, therefore the change of the node number of the top layer of plate represents the change of load case. To find the mesh effects on the optimal topology of plate, a heuristic approach, floating reference strain energy density (SED) interval method, is proposed. Detailed numerical examples are presented. From the final topology results, it is concluded that: 1) if the plate is divided into more layers, in the final topology there is more material distributed far from the central plane and the bottom and top layers have higher volume ratios. The reason is that the more material far from the central plane makes the plate stiffer in the cases with the same amount of material. 2) the material distributing between the bottom and top layers is different obviously for different meshing cases. 3) the compliance of the optimal structure decreases when the number of layers increases.