2, Institute of High Performance Computing, A*STAR, Singapore, , Singapore
3, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California, United States
3D micro-architected structural meta-materials are instrumental in light-weight, high-strength, and damage-tolerance engineering applications. The reliability of such materials is often dictated by the mechanical properties of their truss components such as nanowires and nanopipes and their defects, such as notches and voids and also structure-level defects that disrupt the connection of the lattices. An in-depth understanding on the effects of component-level factors such as grain boundaries, surface roughness, sizes, shapes and man-made notches and structure-level factors such as the sizes and shapes of the connection disruptions on the deformation mechanisms and failure patterns of 3D micro-architected meta-materials is of great importance to their fabrication and services with high reliability. In this talk, we will first report our recent progresses in the study of the effects of component-level factors such as grain boundaries, surface roughness, and the sizes, shapes and man-made notches on the plasticity and failure of the components using both computer simulations and mechanical testing. We will then report our recent work on the effect of temperature and component size on the deformation and failure of micro-architected meta-materials under compression and tension using both computer simulations and mechanical testing. Finally, we discuss the effect of structure-level defects (connection disruption) on the failure behavior of 3D micro-architected meta-materials under tension using both finite element modeling and mechanical testing. The present works explore the size effect, temperature and flaw sensitivity of 3D nanolattices and their components using both simulations and experiments, and demonstrates various interesting and unique features of the architected structural meta-materials.