Applicability of Fracture-Based and Strength-Based Criteria to Debonding in Fibrous Composites

Abstract

Both strength-based and fracture-based approaches have been used to predict the onset of interfacial debonding. The methods for discriminating between the two approaches are considered. An appropriate technique for discriminating between the strength-based and fracture-based approaches to interfacial debonding is then adopted and considered in detail for a glass fibre-polypropylene system. It is shown that both approaches are applicable to the glass fibre-polypropylene system when the fibre diameters are small. However, only the strength-based approach is applicable when systems with large fibre diameters are used. These results bring into question the applicability of results from studies of some pull-out models to practical composite systems. Meaningful interpretation of any test result and of pull-out data is only possible with the selection of the appropriate failure criterion.