Static and dynamic bearing failure of carbon/epoxy composite joints

Mechanical fastening is a common method used to join composite materials in aeronautical industry. Various studies have been performed dedicated to the behaviour of composite bolted joints under quasi-static loadings, but only few studies deal with the dynamic behaviour (crash or impacts). The aim of this work is to study the loading rate influence on the bearing response of a carbon/epoxy laminate loaded by a pin. For that purpose, a double shear test fixture has been specially designed to measure the global behaviour and the local response around the pin. Infrared thermography and Digital Image Correlation techniques have been used to detect, map and characterize dissipative phenomena evolution. The tests have been performed on a servo-hydraulic jack with a loading rate ranging from 10(-4) m/s to 1 m/s. An increase of the peak bearing load of more than 20% is observed with the loading rate increase. A decrease of the load plateau of more than 60% is obtained. Simultaneous measurements of thermal and kinematic fields in this work give access to the evolution of the damage-related dissipative phenomena close to the pin. These dissipative phenomena were found to be significantly dependent on the loading rate.