Dynamic Behaviour of Foams and Sandwich Panels under Shock Wave Loading

Abstract

Sandwich panels with cellular cores are being widely used as blast mitigation materials, due to their light weight and good energy absorption properties. In the present study, the behaviour of sandwich panels against different shock loadings is evaluated using piston driven shock tube. The sandwich panels are fabricated using aluminium(Al) foam core and E-glass/epoxy composite face sheets of different thicknesses. Different shock loads were generated by varying the driven gas pressures. The foams and sandwich panels were subjected to peak shock reflected pressures ranging from 50 bars to 150 bars and the corresponding transmitted pressure pulses were recorded. The behaviour of the foams and sandwich panels under shock wave loading was evaluated by post test visual damage assessment. The effect of face sheet thickness on failure mechanisms of sandwich panel is also studied. The failure mechanisms of foams at higher shock pressures were observed to be core crushing and core fracture, whereas sandwich panels exhibited face sheet deflection, core crushing, fibre breakage at back face sheet and back face delamination.