Numerical analysis for impact resistance of nacre-like composites

Nacre is attracting attention in the field of bionic materials due to the lightweight and high-strength properties. Inspired by the micro layered structure of nacre, a 3D Voronoi polygons model of an AA7075-T651/toughened epoxy resin composite was established in Abaqus/Explicit. Cohesive elements are inserted between the tablets to simulate the organic matrix of nacre, and blunt bullets are used as research object of impact load. To investigate the interlocking failure mode of the nacre-like composites, the maximum of 40 layers were set in the tablet thickness direction. Based on the impact resistance process of the nacre-like composites, the mechanical mechanism and damage modes at different resistance stages was researched. In addition, the effects of tablet dimensions on energy dissipation and deformation characteristics are analyzed. The results show that increasing the number of layers and decreasing the tablets within the same layers can increase the energy absorption performance of composite. This is mainly due to the effective improvement of the interlayer interlocking mechanism, which increases the damage dissipation energy and frictional dissipation energy. The research has a reference value for the structural design and resistance mechanism analysis of nacre-like composites in the field of aerospace and insulation.