Experimental and numerical analysis of dynamic rupture of steel pipes under internal high-speed moving pressures

Abstract

This paper reports the experimentation and finite element analysis (FEA) of dynamic ductile rupture of steel pipes subjected to high-speed internal moving pressures. The experimentation included the detonations of tiny explosive cords inside small segments of ordinary gas pipes. A number of specific features of the detonation-driven fracture of cylindrical tubes such as; formation of special fracture surface markings due to cyclic crack growth, flap bulging, and crack curving/branching adjacent to the bulged area were identified. In the analysis part, the overall transient dynamic response of the pipe to detonation loading, the detonation-driven crack growth, the cyclic bulging of the crack flaps, and the resultant crack branching were simulated. The blast simulation was performed using a multi-material arbitrary Lagrangian–Eulerian (MMALE) formulation. The fluid–structure interaction (FSI) was simulated using a coupling algorithm that treated the air as a static media and the pipe as a deformable Lagrangian mesh. The accuracy of the FEA results was verified using analytical solutions and data collected from the tested pipes. The experimentation and analysis clearly showed that the self-similar propagation of the initial axial cracks in the pipe was the incremental cyclic growth governed by the structural waves.