Abstract
The FW-CFRP / Al composite pressure vessel is a vessel in which the liner of Al alloy is covered with a carbon fiber reinforced plastic (CFRP) layer and a glass fiber reinforced plastic (GFRP) layer by the filament winding (FW) method. In order to reduce the weight and strengthening CFRP and Al alloy of vessels while maintaining safety, it is necessary to improve the accuracy of technology for quantitatively predicting the fracture origin of the vessels. Conventional research deals with FW-CFRP / Al composite pressure vessel as isotropic material, and calculations are performed on condition that the velocity of the elastic wave propagates on the surface of the CFRP does not depend on direction. However, when calculating the elastic wave velocity using the elastic modulus of CFRP, the speed varies by up to 3 times depending on its direction, and it is necessary to consider the anisotropy. The fracture origin at burst of FW-CFRP / Al composite pressure vessels was identified from the difference in the propagation time of elastic waves and compared with the results of fractographical observation. We have developed a position identification method considering its laminated structure and anisotropy of CFRP and showed its effectiveness.
