Research on the energy absorption characteristics of lattice composite sandwich structural beams subjected to pure bending loads

Abstract

This paper leverages the experiments and numerical simulations to investigate the flexural energy absorption characteristics and failure mechanisms of truss-type lattice composite sandwich structural beams filled with polyurethanes (PUs) under pure bending loads. The experimental outcomes unveil that PU-filled staggered lattice composite sandwich structural beams exhibit more favorable energy absorption capacities and specific energy absorption (SEA) characteristics when juxtaposed with parallel lattice composite sandwich structural beams and staggered lattice composite sandwich structural beams devoid of PUs. Subsequently, the energy absorption mechanisms of PU fillers in lattice structural beams are analyzed via the scanning electron microscope (SEM) from a microscopic perspective. The numerical simulation for the PU-filled staggered lattice composite sandwich structural beams proceeds with the finite element analysis software under the quasi-static four-point bending (FPB) load. The resulting findings are in fair alignment with the experimental results. The parametric analysis results demonstrate that skin thickness, side length augmentation of lattice reinforcement section, and width diminishment of lattice cells are instrumental to strengthening beams' ultimate flexural capacity and energy absorption. Simultaneously, the failure modes of beams undergo an alteration. Their SEA is solely subject to the side length of the lattice reinforcement section and the width of lattice elements.