Effect of thickness on the impact resistance of flax fibre-reinforced polymer:

Impact properties of flax fibre-reinforced polymer composites were investigated using two different impact test methods, i.e. drop-weight test and Charpy test. The drop-weight impact tests were conducted with varying drop height. For the drop-weight tests, the perforation energy and the energy absorbed by a specimen are used to study the impact response of the flax fibre-reinforced polymer composite. In a series of Charpy tests, the energy absorbed per unit width of the specimen was investigated. Impact force and Hertzian force were analysed and were found to increase with composite thickness. The ductility index decreased as the composite thickness increased. The failure of flax fibre-reinforced polymer composites started as micro-cracks, progressed to larger cracks and perforation occurred at last. However, the damage to flax fibre-reinforced polymer composites differed with the thickness of the specimens.