Abstract
The penetration and perforation performance of glass-reinforced plastic (GRP) plates containing 20% sand filler has been investigated via quasi-static indentation tests using a sharp-tip (30°) indenter. Two sizes of sand filler (75 and 600 μm) were incorporated in the composite plates to investigate the sensitivity of filler size towards loading system. Also, composite plates were subjected to perforation tests at 5 and 500 mm/min load rates. The investigation successfully used load–displacement behaviours during penetration and perforation by the sharp-tip indenter as a measure for assessing the low-velocity impact performance. The results indicated the clear role played by coarse-sized sand filler as a secondary reinforcement in terms of higher energy absorption. The residual frictional load was up to 45% of maximum perforation load, a considerable gain also due to sand filler incorporation. Composite plates containing coarse-sized filler showed higher energy absorption compared with fine-sized fillers. Higher energy absorption was obtained for plates under high loading rate (500 mm/min). Fibre and matrix fracture constituted the major damage mode in the composite plates tested, followed by delamination. The test results also showed diminishing effectiveness associated with the specific energy absorption of these plates.