The influence of the fiber–matrix microstructure on the energy release rate of off-axis tunnel cracks in laminates

Microstructural effects on the energy release rate and mode mixity for tunneling cracks are investigated. A detailed microstructure is based scanning electron microscopy of a real laminate. Based newly developed two-dimensional off-axis finite element formulation, dependency Mode I, II, III rates range different layup orientations First, influence fiber–matrix microstructures assessed compared to results from homogenized models that exclude explicit representation microstructure. element-based homogenization found provide consistent accurate predictions, whereas analytical methods yield greater discrepancies with respect basic stress-based validation case thus not recommended in context crack modeling. Secondly, realistic non-straight shapes included model resulting similar as straight corresponding fully models. However, modeling without accounting specific provides too low when cases microstructures.