Abstract
For a cryogenic tank of a next generation RLV, a laminated composite tank is one of the key technologies. For the fuel tank made from laminated composites, matrix cracks are significant problems that cause leak of fuel. In the present paper, electric resistance change method is adopted to detect matrix cracking of the laminated composites. Tension load in fiber direction causes electric resistance increase, and fiber breakages also cause the electric resistance increase of the CFRP laminates. In order to distinguish electric resistance changes due to the piezoresistivity and the fiber breakages, gage factor of reloading condition is employed in the present study. Experimental investigations were performed using cross-ply laminates, and as a result, it can be revealed that the gage factor is a useful indicator for matrix crack creation of cross-ply laminates.
