Compliance Correction for Numerical and Experimental Determination of Mode I and Mode II Composite Fracture Failure

This work deals with the determination of the critical strain energy release rate ([image omitted] by means of experimental and numerical methods in unidirectional carbon epoxy composite laminates in modes I and II, and the influence of the test configuration compliance on the results. In previous works, it was found that the determination of GIc by means of experimental procedures and numerical determination using the Finite Element Method (FEM), presented differences in the order of 20-30%. In order to improve the convergence of both numerical and experimental models, research was carried out about the points that could have influenced the results, i.e., FEM element type and size, material behavior law and testing compliance. From this research it was demonstrated that the testing machine compliance had a great influence over the obtained results. The introduction of a correction for testing machine compliance in the calculation has lowered the difference between numerical and experimental results from 20-30% to less than 10% in both modes I and II.