Determination of the interlaminar shear strength of C/C composites by compression shear tests

Recent investigations demonstrated that the standardized tests for the determination of the Interlaminar Shear Strength (ILSS) , e.g. the short-beam-test or the Iosipescu-test, do not yield reliable characteristic strength values. This is due to the complex stress distributions which arise In these set-ups, and in particular, because of the influence of the superimposed normal stresses on the failure behaviour of laminated C/C materials. Therefore, a new procedure was proposed earlier. It consists in grooved specimens which are loaded parallel to the laminae. The behaviour under compressive loading is considered In this paper. Experimental and numerical investigations were performed to optimize the size and the shape of the specimens.