Protection mechanisms and parameter optimization of double-trapezoidal auxetic honeycomb panels under near-field explosion loads

Abstract

Conventional double arrow-head auxetic honeycomb panels (DAHSP) face significant interfacial connectivity issues, while fabricating large-scale auxetic honeycomb structures using alternative cellular microstructures presents additional challenges. To address these issues, a riveted and assembled double trapezoidal auxetic honeycomb sandwich panel (DT-AHSP) was developed to enhance vehicle chassis protection against near-field explosions. However, uncertainties remain regarding assembly coordination, parameter optimization, and protective mechanisms. This study establishes the geometrical relationships among DT-AHSP parameters to eliminate assembly misalignment and derives theoretical formulas for critical dimensions to ensure parameter determination. Laboratory explosion tests validated the finite element model of steel plates covered with DT-AHSP, enabling parametric analyses to assess the influence of structural parameters on explosion resistance. A multi-objective genetic algorithm was applied for structural optimization. Results indicate that the low trapezoidal structure of DT-AHSP effectively supports the deformation of the high trapezoidal structure, and preventing excessive concave deformation. Compared to traditional hexagonal honeycomb sandwich panels and DAHSP, DT-AHSP demonstrates superior protective. Under equal mass conditions, DT-AHSP reduces the maximum displacement of the protected steel plate by 5.5%, while under equal height conditions, the reduction reaches 9.1%, highlighting its practical potential in protective engineering applications.