Study on the dynamic response of octet-truss lattice composite sandwich panels on elastic foundations under blast and boundary loading

Abstract

Based on the Von Karman nonlinear theory and high-order shear deformation theory, a theoretical model of composite sandwich panels (CSPs) was established by considering the constitutive relationship of octet-truss lattice structure into sandwich panels for the first time. The motion equations of model were derived by Galerkin method. The dynamic response of octet-truss lattice composite sandwich panels (O-CSPs) on Winkler-Pasternak foundations under blast and boundary loading was studied by numerical method for solving motion equations using the fourth-order Runge-Kutta method. The effects of different geometric parameters, elastic foundation moduli, boundary loading, damping, explosive quality and explosion distances on the dynamic response of O-CSPs were analyzed. Numerical results showed that when the side length ratio increases from 0.5 to 2, the proportion of declining in amplitude changes from 51 % to 79 %. The proportion of rising in amplitude increases from 15 % to 22 % when boundary loading increases from 0 GPa to 0.24 GPa. The amplitude of O-CSPs changes exponentially with the change of the side length and boundary loading. Pasternak foundation has a better effect of suppressing vibration than Winkler foundation. The dynamic response of the equivalent lattice model was analyzed by finite element method to prove the correctness of numerical results. The blast-proof performance of honeycomb CSPs was calculated and compared with the proposed O-CSPs model to verify the superiority of O-CSPs. The results showed that O-CSPs have lower amplitude and stress level than honeycomb CSPs. The conclusions of this paper can provide the reference for the application of O-CSPs in the field of anti-seismic and blast-proof.