Mixed Mode Crack Initiation and Direction in Circumferentially Cracked Pipes

摘要

In this paper, the S-theory is applied to determine crack initiation and direction for circumferentially cracked pipes.It makes use of a parameter called strain-energy-density factor, S, which is a function of the stress intensity factors. A simplemethod tbr obtai~fing approximate stress intensity factors is also applied. It takes into account the elastic crack tip stresssingularity Mille using the elementary beam theory. Two basic loading conditions in piping systems are studied. The resultsare in reasonable agreement with flae more accurate calculations.