Effect of Water Absorption on the Impact Response of Carbon-Epoxy System Containing Buffer Strips

Instrumented impact testing has been used to evaluate the influence of moisture on the impact resistance of Carbon-Epoxy (C-E) system with buffer strips (BS) incorporated into the laminated composite. Impact tests were done with BS bearing strips posited within the lay-up right below the loading point in one case and away from it in the other. The extent of water ingress was found to increase with increase in the number of BS insertions. While the energy absorption values in plain samples subjected to impact after immersion in water were higher than the corresponding tests on dry samples that for the BS bearing gave varied results depending on the number of BS and their location vis-à-vis the loading point during impact event. The maximum load recorded by various samples, on the other hand, show a general decrease for the water ingressed test coupons. As regards the ductility index values for different set of samples, generally stating, the water immersed BS bearing samples tended to yield lower values.