Investigation on tensile and interlaminar shear of plain woven CMC with Z-pin reinforcement

The tensile and interlaminar shear behaviors of ceramic matrix composite (CMC) with Z-pin reinforcement were investigated. A preform consisting of plain woven fabric and Z-pin through thickness reinforcements was prepared. The process of chemical vapor infiltration (CVI) was used to fabricate the ceramic matrix composite with Z-pins. The tests of uniaxial tensile and unloading-reloading were used to investigate the tensile behavior and the fracture mechanisms of the composite. And a double notch shear (DNS) test was used to investigate the interlaminar shear strength and the fracture mechanism of interlaminar shear. The results show that the tensile stress-strain curve of the plain-woven ceramic matrix composite laminate is nonlinear. Z-pin insertion reduces the tensile strength, and greatly improves the interlaminar shear strength (ILSS) and changes the interlaminar fracture mechanism of the ceramic matrix composite. The debonding of the fabric and the matrix of the interlaminar is changed into double fracture mechanisms of Z-pin shear fracture and the debonding of the fabric and the matrix of the interlaminar.