Chapter 6.1 - Predictive capabilities of nineteen failure theories and design methodologies for polymer composite laminates. Part B: Comparison with experiments

Abstract

This chapter draws together the results from a co-ordinated study, known as the World-Wide Failure Exercise (WWFE), whereby 19 of the leading theories for predicting failure in composite laminates have been tested against experimental evidence. The comparison has been affected through 14 carefully selected Test Cases, which include biaxial strength envelopes for a range of unidirectional and multidirectional laminates and stress-strain curves for a range of multidirectional laminates, loaded under uniaxial or biaxial conditions. The editors organized the WWFE with the following aims in mind: (a) establishing the current level of maturity of theories to predict the failure response of fiber reinforced plastic (FRP) laminates; (b) closing the knowledge gap between theoreticians and design practitioners in this field; and (c) stimulating the composites community into providing design engineers with more robust and accurate failure prediction methods and the confidence to use them. The predictions are provided by the originators of the theories and are made without prior access to the experimental results. In a later and completely separate stage of the exercise the contributors have an opportunity to modify and refine their theories in the light of the experimental results. The predictions and experimental data are compared in a systematic and detailed manner to identify the strengths and weaknesses of each theory and to provide a ranking of the overall effectiveness of each theory. Careful reading of this analysis and study of the figures provided will help to select an appropriate failure theory for use in a given design situation.