Challenges in determination of cohesive laws from r-curves of unidirectional composites experiencing delamination damage

Abstract

With the growing size of wind turbine rotor blades, it is unrealistic to expect composite laminates used in a rotor blade structure to be free from defects. Instead, it would be appropriate to accept that damages will form in these laminates either from manufacturing defects and then try to limit or allow damage growth in a stable manner or arrest. Fortunately, most fibre composite materials are damage tolerant and can exhibit increased fracture resistance under stable damage growth.