Abstract
Fundamental characteristics of stress wave propagating in the fabric reinforced laminates may be more complex than that of non-woven reinforced plastics or the homogeneous materials. Especially, the heterogeneous construction and accompanied internal fracture introduce severe complexities into the behaviour.
The shock propagation due to impact tensil displacement in the lamina was measured to understand the essential characteristics of composites. Also, the shock propagation characteristics were analyzed by FEM (Finite Element Method) by considering the stiffness drop caused by the occurence of micro-fracture as a problem of material non-linearity.
It was made clear the stress wave propagating in the warp fibre bundle arranged along the load direction increased sharply by the occurence of micro-fracture in the weft fibre bundle. The stress waves transmitting in both warp and weft fibre bundle diminished suddenly by the inter-separation between them. The stiffness drop that is generally called“knee”appeared clearly in the numerical results.
