An experimental and analytical investigation of axial crack propagation in long pipes

Abstract Experimental pressure histories, axial and circumferential strains, and crack-opening shapes were compared with the predictions of a simplified model of a fracturing pipe. This model, based upon previous analytical and numerical studies, assumed that the axial strains were negligible. The comparison showed that this assumption was valid only for relatively thickwalled pipes. An analytical energy analysis, based upon experimental data, indicated that the primary energy absorption in thin-wall pipes was the axial stretching of the pipe flaps formed by the propagating crack. The pressure profiles and crack shapes developed by modifying the model to account for the axial strain energy compared well with the experimental results. This good agreement indicates that accurate predictions of dynamic axially propagating cracks may be made using a ring model which will consider the axial energy and the frictional shear forces which exist between longitudinal sections.