Experimental and numerical studies on the quasi-static and dynamic crushing responses of multi-layer trapezoidal aluminum corrugated sandwiches

The axial crushing responses of bonded and brazed multi-layer 1050 H14 trapezoidal aluminum corrugated core (fin) sandwich structures, with and without aluminum interlayer sheets in 0 degrees/0 degrees and 0 degrees/90 degrees core orientations, were both experimentally and numerically investigated at quasi-static and dynamic strain rates. Multi-layering the core layers decreased the buckling stress and increased the densification strain. The experimental and simulation compression stress-strain curves showed reasonable agreements with each other. Two main crushing modes were observed experimentally and numerically: the progressive fin folding and the shearing interlayer aluminum sheets. Both, the simulation and experimental buckling and post-buckling stresses increased when the interlayer sheets were constraint laterally. The multi-layer samples without interlayer sheets in 0 degrees/90 degrees core orientation exhibited higher buckling stresses than the samples in 0 degrees/0 degrees core orientation. The increased buckling stress of 0 degrees/0 degrees oriented core samples without interlayer sheets at high strain rate was attributed to the micro-inertial effects which led to increased bending forces at higher impact velocities. (C) 2014 Elsevier Ltd. All rights reserved.