Evaluation of the apparent interfacial shear strength in short-flax-fiber/PP composites

An important factor affecting the mechanical characteristics of composite materials is the adhesion of constituents which can be characterized by the interfacial shear strength (IFSS). Most of the experimental methods for the evaluation of IFSS involve model single-fiber composites. By contrast, the method proposed by Bowyer and Bader is based on an analysis of the stress–strain curve of a short-fiber-reinforced composite in tension. In the present study, the method is applied to the experimental tension curves of short-flax-fiberreinforced polypropylene to evaluate the IFSS and the fiber orientation factor of the composite. The IFSS was found to depend on the volume fraction of fibers and the treatment to improve adhesion.