Failure processes governing long term reliability of carbon fibre composites structures

Abstract : Advanced composites are now used in many critical civil applications for which long term reliability is an absolute necessity. Testing based on more traditional metal structures has been shown to be inappropriate and there is a pressing need to develop new tests based on an understanding of damage processes in composite structures. Multi-scale modelling which takes into account the characteristics of the fibres, matrix and fibre/matrix interfaces is now well developed. It allows the kinetics of fibre failure during monotonic loading and sustained loading of composites to be explored and identifies the critical damage levels leading to failure for these loading conditions. This information allows safety factors based on the intrinsic properties of the composites to be determined and quantified.