Mechanical characterization of metal additively manufactured contact aided cellular compliant mechanisms

Additive manufacturing allows for the creation of complex geometries that can be optimized for performance. However, understanding the effect of the manufacturing process on part performance is essential to balance performance with manufacturability. In this work, a cellular contact aided compliant mechanism previously designed by the authors is manufactured using laser powder bed fusion. Failure modes for C3M lattice design are highlighted and recommendations for manufacturability are obtained. The mechanical response of C3Ms is characterized through compression testing of lattice and single cells. Compression testing is used to understand the mode of energy absorption of C3M lattices and compare with mechanical simulations. Lattices with large wall thickness and largest cell size are found to absorb the most strain energy. The increase in stiffness of the C3M lattice is found to depend on the thickness of the cell walls and size of the contact gap. The failure modes based on manufacturing and mechanical test data are synthesized to generate design rules for selecting C3M geometry to minimize manufacturing defects and maximize performance.