Dynamic Fracture and Depressurization in Pipes

摘要

This annual report contains predictive models for initiation and rapid propagations of ductile axial and circumferential cracks and the associated depressurization response in pipes developed during the sixth year of EPRI RP 231-1.nThree dimensional static stress intensity factors of circumferential through cracks of various crack lengths and in a pipe subjected to uniform axial tension, uniform axial displacement, pure bending at pipe ends and three point bending with the crack on the tension side were obtained. The thermal hydraulic code LEAKER as well as, an updated version of a closed form solution of depressurization equations for large, axial-crack-induced breaches were used to predict the depressurization and maximum rate of depressurization of axially cracking pipes. Both methods pro¬vided depressurization rates which were in excellent agreement with the data ob¬tained by the Central Electricity Generating Board.