FIBER MATRIX INTERFACE PROPERTY DETERMINATION

A 'microcomposite' single fibre pull-out test has been designed to permit the visual observation of events at the fibre/matrix interface and the collection of detailed mechanical data as interface debonding and fibre pull-out occur. The confirmation of a uniform strain gradient distribution along the embedded length of fibre by birefringence observations allows simple determination of the interfacial shear strength using the quotient F(deb)/A(int), where F(deb) is the interface debonding force and A(int) is the interfacial area given by 2-pi-rl. Several characteristics displayed by the load/displacement measurements have been directly correlated with observed events such as fibre stick-slip and interfacial frictional effects.