Damage in woven-fabric composites subjected to low-velocity impact

The behaviour of woven-fabric laminated composite plates has been studied under transverse central low-velocity point impact by using a modified Hertz law and a 3D transient finite-element analysis code. The in-plane failure behaviour of the composites has been evaluated by means of a failure function based on the Tsai-Hill quadratic failure criterion. The effect of fabric geometry on the impact behaviour of woven-fabric composites has been studied. For comparison, the impact behaviour of balanced, symmetric, crossply laminates made of unidirectional layers and unidirectional composites has been included. The studies have been carried out with plate dimensions of 150 mmx150 mmx6 mm for a supported boundary condition. For these studies, incident impact velocities of 3 and 1 m/s and an impactor mass of 50 gm have been used. It is observed that the in-plane failure function is lower for woven-fabric laminates than for crossply laminates, indicating that woven-fabric laminates are more resistant to impact damage. (C) 2000 Elsevier Science Ltd. All rights reserved.