Mechanical behaviour of a pipe impacted by an object, based on numerical simulation

Abstract

DAMAGE TO A PIPE squeezed by other object are one of the key damages for oil and gas pipelines. Mechanical behaviour of a pipeline section in a deformed state was investigated by numerical simulation. Effects of initial dent depth and pipe diameter / wall thickness ratio on the mechanical behaviour of the dented pipe were studied. The results show that the squeezing force, high stress area, and the maximum stress increase in the loading process. In the unloading process, there is a high probability for recovery of the pipeline section elastic strain to initial values. Cross-section of the middle plane is flatted. The deformation of the pipe in the vertical plane is V-shaped. In the first stage, the maximum equivalent plastic strain appears in the centre part of the pipe. There are two maximum equivalent plastic strain areas with the increasing of the squeezing object’s displacement. In the unloading process, the equivalent plastic strain increases. With the increasing of the initial indentation depth, the resilient rate of the pipe dent decreases, but the maximum equivalent plastic strain increases. With the increasing of pipe diameter / wall thickness ratio, the resilient rate increases but the maximum equivalent plastic strain decreases.