Experimental push out testing and analysis of fibre reinforced composites: applicability and test considerations

Abstract

The applicability of the push out technique to fibre composite systems with both excellent and poor interfacial bonding has been considered through experimental push out studies on model polymer matrix and metal matrix composite systems, respectively. Some factors which affect the reliability and reproducibility of data from the push out test have also been established. The findings are applicable to ceramic matrix composites. The interfacial properties of the model steel fibre/epoxy matrix, copper fibre/epoxy matrix, steel fibre/aluminium matrix, and SiC fibre/aluminium matrix composite systems were studied. Factors which influence the reproducibility of interfacial properties such as the interfacial bond strength and the matrix shrinkage pressure as determined from the push out test have been identified. These include the thickness/fibre diameter ratio, the relative diameter of the fibre and the specimen, and the aspect ratio of the fibre in the push out specimen. It was also important to establish the nature offailure at the interface.