A modified Q4/Q4 element for topology optimization

Design variable and displacement fields are distinct. Thus, their respective material and finite element meshes may also be distinct, as well as their actual location of nodes for the two fields. The proposed Q4/Q4M element possesses design variable nodes and displacement nodes which are not coincident. The element has been implemented using different approaches, including continuous approximation of material distribution and nodal approaches. The results obtained demonstrate that the element is effective in generating structural topologies with high resolution. From a numerical point of view, mesh independent solutions can be obtained by means of projection.