Statistical energy and failure analysis of CFRP compression Behavior using a uniaxial microbuckling model

Compression failure followed by fragmentation is a pre-eminent energy absorption mechanism in fiber-reinforced composites and, therefore, it is often used in crash absorption devices. Fragmentation is the last stage of degradation leading to total failure of a carbon fiber reinforced plastic (CFRP) laminate in compression. Micromechanical studies have shown that this phenomenon is initiated mainly by a microbuckling mechanism which depends on microstructural imperfections (fiber misalignment and matrix plasticity). As far as energy absorption and dedicated modeling strategies are concerned, the question is whether the failure scenario is dependent on these imperfections in terms of dissipated energy. In this context, we used a one-dimensional microscale approach to model plastic microbuckling and evaluate the corresponding dissipated energy for a realistic range of microstructural parameters (with statistical treatment). Contrary to our expectations and to the well-known sensitivity of the peak loads, these energies seem unaffected by microscopic parameters. In conclusion, we propose some ideas on how to include the main aspects of fragmentation, which can occur in composite materials under in-plane compression loading, on the mesoscale.