Composites A, Applied Science and Manufacturing vol:32 issue:10 pages:1465-1475
A progressive damage model is presented for the prediction of the overall non-linear tensile behaviour of knitted fabric composites. The model is an extension of a recently developed inclusion method for textile composites, taking into account the major damage modes of knitted fabric composites simultaneously. Matrix non-linearities, playing an important role in the behaviour of knitted fabric composites, are implemented using the secant stiffness method. Whereas, non-linearities can be attributed to different sources, depending upon the resin toughness, only some limited yielding was currently investigated. Yam/matrix debonding, predominantly responsible for the knee behaviour of knitted fabric composites, is investigated using a simple interfacial failure criterion. A selective degradation scheme based upon a finite set of interfacial damage state variables is employed in the reduction of the inclusion stiffness. Finally, a Hoffman criterion is used for yam failure. The model was used to simulate the tensile behaviour of knitted fabric E-glass/epoxy composites, showing the ability to predict the material response with reasonable accuracy in the region before ultimate failure. (C) 2001 Published by Elsevier Science Ltd.