LAUSR

Abstract This paper presents multi-scale modeling and nonlinear low-velocity impact analysis of sandwich plates with graphene reinforced composite (GRC) face sheets and functionally graded (FG) auxetic 3D lattice cores. The temperature-dependent material properties of GRC face sheets are determined through a micromechanical model of extended Halpin-Tsai type. The 3D lattice cores are designed to have negative effective Poisson's ratios (EPRs) and possess two FG configurations through the plate thickness direction. Considering the localized deformation and accompanying shape and effective properties changes of 3D lattices, a full-scale FE simulation was then conducted. Numerical results demonstrated that, when compared with their non-auxetic compactors, the auxetic 3D lattice cores can bring about significantly enhanced impact resistance. Moreover, distinct effects of FG configurations are found on both the back face sheet displacements and contact forces of sandwich plates subjected to a rigid spherical impactor. Numerical results show the superiority of FG auxetic lattices. The present model is expected to be instructive for potential engineering applications and beneficial for further research.