Response characterisation in CFRP notched coupons with energy-based multi-axial failure data

A methodology that uses multi-axial testing and dissipated energy (DE) to characterise the mechanical behaviour of laminated composite materials has been further extended to make use of intuitive relationships between material stiffness and DE. The methodology is able to accurately predict the initiation and early progression of damage providing valuable information on the location, intensity and behaviour of damage in a composite specimen. A constitutive relationship was implemented in which the material stiffness was degraded based upon the total work and dissipated energy. The resultant material behaviour demonstrated that response characterisation of composites with complex failure modes using DE is possible, even when employing a simplistic relationship. This suggests a more detailed constitutive relationship will lead to a more accurate prediction of load response and damage behaviour of composite materials.