Experimental analysis of thermal and damage evolutions of DCFC under static and fatigue loading

Discontinuous carbon fibre composite (DCFC) is a new low-cost material that has already been applied for commercial components, such as window frames of the Boeing 787 Dreamliner. Studying DCFC is very challenging because it does not show the same behaviour than conventional composites or isotropic materials. This work presents an experimental study of DCFC specimens submitted to static and fatigue tensile loading, based on mechanical and thermography non destructive evaluation (NDE) technique. An infra-red (IR) camera is used for real time monitoring of temperature change at the specimen outer surface. Under static loading, thermal response permits to well detect the early appearance of micro defects up to the final failure of DCFC material. Moreover, thermal response gives a good correlation with the damage evolution under fatigue loading. It is also shown that thermography method allows to successfully determine the high cycle fatigue strength (HCFS) of DCFC material.