Interlaminar fracture characterization of a carbon-epoxy composite in Pure Mode II

Abstract

The interlaminar fracture toughness in pure mode II (GIIc) of a Carbon-Fibre ReinforcedPlastic (CFRP) composite is characterized experimentally and numerically in this work, using theEnd-Notched Flexure (ENF) fracture characterization test. The value of GIIc was extracted by a newdata reduction scheme avoiding the crack length measurement, named Compliance-Based BeamMethod (CBBM). This method eliminates the crack measurement errors, which can be nonnegligible,and reflect on the accuracy of the fracture energy calculations. Moreover, it accounts forthe Fracture Process Zone (FPZ) effects. A numerical study using the Finite Element Method (FEM)and a triangular cohesive damage model, implemented within interface finite elements and based onthe indirect use of Fracture Mechanics, was performed to evaluate the suitability of the CBBM toobtain GIIc. This was performed comparing the values of GIIc inputted in the numerical models withthe ones resulting from the application of the CBBM to the numerical load-displacement (P-)curve. In this numerical study, the Compliance Calibration Method (CCM) was also used to extractGIIc, for comparison purposes.