AXIAL RUPTURE OF LARGE-DIAMETER, GAS-PRESSURIZED, STEEL PIPES

As part of an experimental programme to characterise the internal and external fluid dynamic forces generated by failure of high-pressure pipework, the development of an axial breach in large gas-pressurised steel pipes has been studied. Eight 610 mm diameter pipes with wall thicknesses of either 6. 2 or 9. 3 mm and two pipes of 915 mm diameter with 9. 3 and 12. 5 mm wall thicknesses were ruptured. Results are presented for the variation of breach area with time, for fracture velocity, strain and strain rates near the fracture path, and for the internal depressurisation transient. Theoretical upper limits for ductile shear and cleavage fracture velocities are shown to be valid and a characteristic time for the breach development process, derived from a simple theoretical model, successfully correlates the experimental breach growth data.