The Influence of Mode-Mixity on Dynamic Failure Mode Transitions in Polycarbonate

Overview & Synopsis

The transition of a shear to opening type of failure mechanism has been reported for side impact experiments of notched or cracked plates (metallic alloys and Polycarbonate). The present paper addresses additional aspects of the phenomenon in relation to mode-mixity for actual fatigue cracks in Polycarbonate specimens. Two distinct experimental setups are used and systematically compared throughout the work: dominant mode II and dominant mode I loading. The experimental results show that the same characteristic failure mechanisms operate irrespective of the specimen geometry (loading mode) and crack-tip nature for a given impact velocity (evolution of the stress intensity factors).