Statistical Mechanical Breakdown of Single Fibres and Microcomposites Using Video Microphotographic Techniques

Abstract

Using polymeric fibre strength data from the literature and from our own laboratory tests, we show in the first part of the present paper that simple modifications of Poisson/Weibull concepts, resulting in a new failure probability function, can be used as a modeling scheme for the study of diameter effects on strength in a way at least as satisfactory as previously used LEFM-based schemes. In the second part of the paper a new experimental approach for the study of composite failure is presented. Specially prepared composite monolayer models were tested in simple tension under an optical microscope equipped with crossed polarizers and with a video camera. The potential usefulness of this approach for the characterisation of basic failure modes in fibre-reinforced composites, and as a probe of existing strength theories in such materials, is demonstrated.