A Pressure Decompression Model-Based Finite Element Approach for Efficient Dynamic Fracture Analysis in CO2 Pipelines

Abstract

Running fractures represent the most catastrophic failure mode in CO₂ pipelines. Traditional engineering methods for crack prediction have proven non-conservative, while existing fluid–structure interaction (FSI) models suffer from computational inefficiency. This study proposes a novel finite element simulation method based on an innovative three-dimensional pressure decompression model that effectively characterizes CO₂'s unique thermodynamic behavior during pipeline fracture. The methodology involves three phases: establishing a simplified yet physically accurate pressure decompression model through systematic analysis of experimental data; validating the approach through full-scale burst tests, demonstrating superior computational efficiency compared to conventional FSI methods while maintaining high accuracy; and conducting comparative analyses that reveal fundamental differences between CO₂ and natural gas pipeline fracture behavior, including larger crack-tip opening angles and more extensive plastic deformation in CO₂ pipelines. These findings advance understanding of CO₂ pipeline fracture mechanisms and provide an efficient computational framework for parametric studies essential for pipeline safety design.