Three-point bending behaviors of the foam-filled CFRP X-core sandwich panel: Experimental investigation and analytical modelling

Abstract

To enhance the energy absorption capacity of the sandwich structures, the foam filled composite X-core sandwich panels were fabricated by a hot-press molding technology. The bending behaviors of the empty and hybrid composite sandwich panels were investigated by the three-point bending tests. Analytical models and finite element models were developed to characterize the bending behaviors and the interaction effect between the foams and composite members. Generally, the specific bending modulus and strength of composite X-core sandwich structures are comparable to that of the competing cellular structures. The theoretical expressions can provide useful predictions of the bending stiffness and initial failure load, whilst the numerical models had a higher accuracy. A failure mechanism map was constructed to highlight the effect of geometry parameters on the failure modes. A minimum weight design was employed to provide a guideline for obtaining the weight-efficient hybrid composite sandwich panels.