The compressive responses and failure behaviors of composite graded auxetic re-entrant honeycomb structure

This paper investigated the quasi-static compressive performances and failure behaviors of composite auxetic re-entrant honeycomb sandwich structure. Three types of auxetic re-entrant honeycomb structures with different gradient configurations were manufactured and tested. The carbon/epoxy prepreg was used to fabricated the auxetic re-entrant honeycomb sandwich structure. The reaction force and displacement of the test fixture were collected by the transducer of the universal testing machine. The compressive processes of specimens were recorded by high-resolution camera. Combined with the stress–strain curves and deformation processes of composite structures, the compressive responses and deformation mechanisms was analyzed. The Poisson's ratio, energy efficiency and plateau stress of re-entrant honeycomb sandwich structures were defined and utilized to study the auxetic performance and energy absorption ability. Furthermore, a high-fidelity numerical model was established and finite element software ABAQUS was used to analyzed the compressive performances and failure behaviors of composite graded auxetic re-entrant honeycomb structure. The compressive failure modes of the numerical simulation results were compared with that of the experimental results, and the numerical simulation results agreed well with the experimental results. The results indicated that average structure exhibited best energy absorption performance and bidirectionally graded auxetic honeycomb structure had the best negative Poisson's ratio performance.