On phenomenological failure criteria for composite bolted joint analysis

Abstract

There has been a recent trend to use phenomenological strength models in combination with point stress or average stress failure criteria to form strength models for the analysis of composite bolted joints. Several papers published using these approaches have demonstrated practical reductions in the size of the empirical data base required to perform bolted joint analysis for specific materials and laminates. Since the inception of phenomenological failure models for bolted joints several refinements have been proposed, but the generality of the method is not clearly defined. This paper addresses the concepts underlying the formulation of these strength models, compares the capabilities of several commonly used failure criteria and discusses the limits of applicability through example analyses and comparison with experimental data. The results indicate that differences in predicted strengths for the models examined were insignificant. Failure mode predictions based on single point failure location information varied from model to model and differed significantly from experimentally observed failure modes for some geometries. The models cannot be applied with confidence for the analysis of a wide class of laminates and geometries without calibrating the model through empirical data.