Experimental study of off-axis compression behaviour in dynamic loading: The open hole effect

The effect of the open hole on the behaviour of carbon fibre reinforced polymer composites (CFRP) under compressive dynamic loading was investigated. To this end, two different set-ups (quasi-static and dynamic) for compression loading were developed. The un-notched plain woven CFRP (AS4 fibres and 8552 matrix) studied in this work was characterized in terms of apparent strength at different off-axis angles at compression loading. The maximum stress criterion was found to be the model which better represents the transverse-shear failure points of the woven composite. Later the effect of the open hole in similar samples were studied, concluding that the hole effect has more impact on the strength for samples with the fibre align with the load. A modification of the Lekhnitskii theory has been proposed in order to take into account the non-linearity of the material and to unveil its role in open hole specimens.