Paper number 774

ON THE MATURITY OF WORLD-WIDE FAILURE THEORIES: COMPARISON WITH EXPERIMENTS FOR GRP LAMINATES

M J Hinton¹, P D Soden² and A S Kaddour²

1 Structural Material Centre, Defence Evaluation and Research Agency (DERA), Fort Halstead, Sevenoaks, Kent, TN14 7BP, UK.
2 Mechanical Engineering Department, UMIST, Sackville Street, P O Box 88, Manchester, M60 1DQ, UK
(c) British Crown Copyright 1999, Defence Evaluation and Research Agency

Summary

The authors are coordinating a 'World-Wide Failure Exercise' to establish the current status of theoretical methods for predicting structural failure in fibre reinforced composites materials. The exercise runs in two parts. Part A is devoted to providing full details of the theories together with predictions, made by their originators, for a standard set of test cases. Part B is concerned with comparing the theoretical predictions with experimental results. This paper is directed at exposing some of the early lessons resulting from Part A. Particular attention is focussed on three 'Test Cases', all involving (55O angle ply laminates. Theoretical predictions and experimental results are presented for the in-plane biaxial failure envelopes. Preliminary conclusions are drawn as to the degree of maturity of the current theories in dealing with the progression to failure, under a wide range of lamina combined stress states.

Keywords

failure, laminates, biaxial, stresses, strength.