Quasi-static crush behavior of hollow microtruss filled with NMF liquid

Nanoporous materials functionalized (NMF) liquid has high energy absorption efficiency which holds great promise in advanced protective and damping devices. In this work we incorporate the NMF liquid into hollow microtruss structures to construct a superior energy absorption system. The compressive deformation map of hollow microtruss is given, and then the yielding criterion of NMF liquid filled microtruss is proposed. The quasi-static crush behavior is systematically studied through FEM simulation, then the plastic deformation of the microtruss and NMF liquid are analyzed in detail. By filling NMF liquid into the microtruss the plastic buckling of the microtruss is effectively suppressed, so as to improve the load capacity as well as energy absorption efficiency more than two times for relative thin microtruss (t/R < 0.02). The origin of the energy absorption enhancement comes from two parts: one is the volumetric plasticity of NMF liquid and the other part is plastic deformation enhancement of the microtruss. Furthermore, the strain hardening effect of the materials of microtruss can further improve the energy absorption of NMF liquid filled microtruss as the microtruss can hold larger infiltration pressure and reduce the plastic strain localization in the wrinkles of the microtruss to avoid the leaking of NMF liquid. (C) 2014 Elsevier Ltd. All rights reserved.