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 CO 2 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 CO 2 '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 CO 2 and natural gas pipeline fracture behavior, including larger crack‐tip opening angles and more extensive plastic deformation in CO 2 pipelines. These findings advance understanding of CO 2 pipeline fracture mechanisms and provide an efficient computational framework for parametric studies essential for pipeline safety design.