Predicting the nonlinear response and failure of composite laminates: correlation with experimental results

A comprehensive comparison of laminate failure models was established to assess the state-of-the-art in laminate modeling technologies on an international level (known as the Worldwide Failure Exercise) [Compos. Sci. Technol. 58(1998) 1001,1011,1225]. In our first contribution to this Exercise (Part A), we presented a complete theoretical description of an analysis methodology and documented predictions for the laminate response and failure behavior of various laminates under a broad range of loading conditions [Compos. Sci. Technol. (in press)]. This paper represents our contribution to Part B of the Exercise where the laminate response and failure predictions for fourteen different cases are presented and compared with actual experimental test data. The cases include prediction of the effective nonlinear stress vs. strain responses of laminates, as well as, initial and final ply failure envelope predictions under multi-axial loading. Correlation between the theoretical predictions and experimental results are discussed. While reasonable correlation was achieved, the failure analysis employed by the authors was not universally accurate in predicting the laminate failure response for the broad range of test cases considered. This statement, although not surprising, is likely true for any given failure methodology as it is applied to a wide range of laminate lay-ups and loading conditions.