Quasi-static and impact damage of thermoplastic composites: Micro-macro experimental approach

We developed a micro-macro experimental approach to understand the damage and fracture behaviour of cross-ply thermoplastic composites subjected to out-of-plane loading. Firstly, cross-ply laminates were subjected to quasi-static loading in order to evaluate the damage pattern. Next, we performed low-velocity impact at various impact energies, and observed the damage due to impact. Since it is difficult to track the damage behaviour at plate level, we developed a micro-scale test device (micro-3-point-bending or micro-3PB) to capture the principal damage mode (transverse crack and delamination) through the use of unsymmetrical-unbalanced cross-ply laminate. We found that the physics of degradation (damage mechanism) at macro-scale can be qualitatively captured with our micro-3PB setup.