Design and experimental verification of self-supporting topologies for selective laser melting

Abstract Self-supporting design is an important issue that needs to be considered in the combination of topology optimization (TO) and additive manufacturing (AM). In this paper, the self-supporting and printable Messerschmitt–Bolkow–Blohm (MBB) beams of Ti6Al4V alloy are designed by combining Solid Isotropic Microstructure with Penalization method (SIMP) with Langelaar's AM filter and manufactured by selective laser melting (SLM). Then the formability and the bending behavior of experiments and simulation for MBB beams are investigated. The results reveal that TO can reduce the structural weight for AM effectively. Moreover, the MBB beams have the best formability when the volume fraction is greater than 0.3. Under bending loads, the overall performance of MBB beams improves with the increase of the volume fraction. Among them, the specific stiffness and comprehensive performance of the variable-section MBB beams (3D, VS-MBB) are superior to those of the constant-section MBB beams (2D, CS-MBB). When the volume fraction is around 0.4, the VS-MBB beams have the best formability and specific stiffness. Furthermore, MBB beams have two failure modes: the failure of the thin rods in the structures, and the crushing failure on the loading position. Finally, the ABAQUS simulation results are consistent with those of experiments within the permissible error evaluation, which will provide potent guidance for future researches.