Numerical simulation on in-plane deformation characteristics of lightweight aluminum honeycomb under direct and indirect explosion

Abstract

Lightweight aluminum honeycomb is a buffering and energy-absorbed structure against dynamic impact and explosion. Direct and indirect explosionswith different equivalent explosivemasses are applied to investigate the in-plane deformation characteristics and energy-absorbing distribution of aluminum honeycombs. Two finite element models of honeycombs, i.e., rigid plate-honeycomb-rigid plate (RP-H-RP) and honeycomb-rigid plate (H-RP) are created. The models indicate that there are three deformation modes in the X1 direction for the RP-H-RP, which are the overall response mode at low equivalent explosivemasses, transitional responsemode atmediumequivalent explosivemasses, and local responsemode at large equivalent explosivemasses, respectively. Meanwhile, the honeycombs exhibit two deformationmodes in the X2 direction, i.e., the expansionmode at low equivalent explosive masses and local inner concave mode at large equivalent explosive masses, respectively. Interestingly, a counter-intuitive phenomenon is observed on the loaded boundary of the H-RP. Besides, the energy distribution and buffering capacity of different parts on the honeycomb models are discussed. In a unit cell, most of the energy is absorbed by the edges with an edge thickness of 0.04 mm while little energy is absorbed by the other bilateral edges. For the buffering capacity, the honeycomb in the X1 direction behaves better than that in the X2 direction.