Identifying microstructural features initiating compressive failure in unidirectional fibre-reinforced polymers

The industrial applicability of advanced fibre-reinforced polymers (FRPs) is limited by their compressive performance. This study aims to uncover the microstructural features that influence unidirectional (UD) FRP compressive failure. This was undertaken through computational simulation of virtual 2D UD-FRP microstructures with systematically varying fibre misalignment angle θ f field statistical and spatial parameters. For each FRP, the location of maximum matrix plastic strain at peak global stress was taken as the failure initiation site location. Locations of maximum θ f , maximum fibre volume fraction V f , and minimum V f for each FRP were also identified; the typical microstructural ( θ f and V f ) features about such locations were compared against those of the failure initiation site locations. The results showed that UD-FRP failure initiation location could not be predicted using the magnitude of θ f or V f alone, and must include significant consideration of local spatial variation of the property fields as well. This study has highlighted the critical role of microstructural spatial patterns, in addition to the magnitudes of θ f and V f , in influencing the underlying micromechanics of UD-FRP failure initiation.