Research on stress intensity factors of external surface cracks of pipeline
Cracks in oil and gas pipelines will reduce the load carrying capacity of the pipelines,and even bring dangers.Therefore,studying the safety of cracked pipelines with internal pressure has become an urgent issue.Taking the hemispher-ical pipeline with surface cracks as the research object,the change of von-Mises and stress intensity factor of the crack body are studied by the joint simulation of FEA software and three-dimensional crack analysis software.The results show that if the tilt angle and depth of the radial crack increase,the stress concentration of the leading edge of the crack will increase.With the increase of crack inclination angle,the stress intensity factor of type Ⅰ crack and the J integral will decrease,while the stress intensity factor of type Ⅱ and Ⅲ cracks will increase.Increasing the depth of elliptical crack will increase the stress intensity factor of type Ⅰ crack and the J integral at the crack front,but the growth rate of the values at both ends is fas-ter than that at the tip.With the increase of crack length,the stress intensity factor of type Ⅰ crack and the J integral growth rate near the crack tip are larger than those at both ends of the crack.The research results can provide technical support for pipeline crack growth and control.
NETL
NSTL
万方数据
维普
