Blast Performance and Damage Assessment of Composite Sandwich Structures

Abstract

This chapter reviews blast experiments that have been carried out on composite sandwich panels with glass-fiber reinforced polymer (GFRP) face-sheets, carbon-fiber reinforced polymer (CFRP) face-sheets and face-sheets containing a mixture of fiber fabrics. The panels were subjected to explosive charges ranging from 1.28 to 100 kg TNT equivalent during the air and underwater blast tests. The difference in panel response was recorded using high-speed photography and digital image correlation (DIC) during the air blast tests. More conventional instrumentation using strain gauges was required for the underwater blast tests. Following each experiment, the panel damage was analyzed and compared either visually or using X-ray computed tomography (CT) scanning. The addition of polypropylene (PP) Innegra interlayers into a GFRP front face-sheet has been shown to be advantageous during air blast loading. Due to the increased thickness of the front face-sheet, the panel deflects less and experiences less front face-sheet damage. The replacement of GFRP plies with aramid plies during underwater blast loading was shown to be detrimental to the panel performance. The panel suffered from more severe damage compared to a fully GFRP panel. The comparison of CFRP against GFRP panels during underwater blast revealed that the CFRP has a greater stiffness but this result in greater face-sheet debonding due to its lower strain to failure. These experiments have shown that an optimal blast resilience response could be achieved through the combination of different fiber fabrics.