Numerical study on the effects of multiple initial defects on the collapse strength of pipelines under external pressure

A numerical simulation study explores the effects of initial defects on the collapse strength of pipelines under external pressure, with a focus on the coupling effect of multiple initial defects. The collapse strength of pipelines with only one initial defect is studied and the effects of the length and amplitude of the defect are determined. Then, pipelines with multiple initial defects are analysed and the effect of the distance between two initial defects is investigated. The critical distance between defects is determined in order to determine whether there exists any coupling effects between defects. In the case of coupling, the equivalent length of the two initial imperfections is derived. Based on the calculation results a simplified equation is proposed to describe the ultimate collapse strength of pipes with localised initial defects.

Automated summary

The study examined the impact of initial defects on the collapse strength of pipelines, focusing on the coupling effect of both single and multiple initial defects. Factors such as defect length, amplitude, and distance between defects were analyzed for their effects on pipeline strength.