Experimental and Numerical Study of Delamination Growth Induced by a Transverse Crack in Unidirectional Laminates Subjected to Bending Loads

This paper presents the results of an experimental and numerical investigation into the mixed-mode delamination growth initiated from a transverse crack in unidirectional laminates under the three-point-bend test condition. The delamination growth was found to be stable both numerically and experimentally. Two data reduction methods, the compliance calibration and the finite element-based data reduction, were used to analyze test results. It was shown that the latter method gives better results. The finite element delamination growth modeling incorporating the linear growth criterion was also used to model the growth of delamination. Very good agreement between numerical and experimental results was achieved. This type of specimen has the advantage of being very easy to prepare. There is no need to implant an artificial delamination as required for most interlaminar tests. The data reduction method using finite element analysis is straightforward. Therefore, this type of test specimen can be used effectively for determination of mixed-mode fracture toughness of laminated composites.