Study on crack tip opening angle evolutions during dynamic crack propagation of pipelines

Abstract Crack tip opening angle (CTOA) has been used to describe the arrest toughness of high‐grade pipelines. However, its evolutions and influencing factors during pipeline crack propagation are unclear. In view of this, this paper reproduces the full‐scale test using a numerical simulation method that is proven to be reliable. On this basis, the evolutions of CTOA during the dynamic crack propagation of the pipeline are systematically studied, and the effects on CTOA values are clarified. The results show that the critical CTOA of a pipeline is independent of the design factor, the pressure decompression, and the large change in the crack velocity and is also not sensitive to the pipe strength, pipe wall thickness, and the inertial effect of soil, but only related to the pipe diameter and pipe toughness. The above conclusions have laid a foundation for the subsequent establishment of the arrest control method for natural pipelines based on CTOA.