Burst pressure of thin-walled pipes with dent and gouge defects

Abstract

Mechanical interference is the main cause of the failure of thin-walled pipelines in some countries. Gouges and dents are two common types of external interference that threaten the structural integrity of thin-walled pipes. This paper presents an experimental and numerical investigation of the failure pressure and strain history of thin-walled pipes with dent and gouge defects. First, four full-scale burst tests were conducted. Then, a 3D nonlinear finite element model was established, and its accuracy and reliability were validated using the experimental data. On the basis of the experimental and numerical results, the failure pressure of the thin-walled pipes with dent and gouge defects was studied in detail. During the burst process, the variation in axial strain is small, whereas the circumferential strain changes significantly. Test results show that failure location occurred at the flank of dent. Pipe deformation is more prominent for small defects. A parametric study suggests that the failure pressure increases with decreasing dent depth, pipe diameter-to-wall-thickness ratio, and gouge depth and length. The gouge size has the strongest effect on the failure pressure of thin-walled pipes with dent and gouge defects.