Edge machining effects on the failure of polymer matrix composite coupons

Abstract

This papers deals with the influence of the machining procedure of carbon/epoxy and glass/epoxy composite coupons on their mechanical performances. First, a literature review is presented to summarize the rather small number of studies dedicated to this subject. Then, machining procedures are detailed and evaluated by surface roughness measurements and microscopic observations. Finally, results of Iosipescu shear tests and ring tension tests are reported and discussed. The main conclusion of this study is that there is a significant effect of machining procedure on composite coupons strength for certain sets of parameters but that surface information (roughness, microscopic observation) is not enough to explain them. Further work is necessary on this subject to derive relevant machining quality criteria with a view to mechanical performance.