关键词: X80, 体积型缺陷, 气体长输管道, 安全评价, 有限元模型, 应力分布, 非线性有限元

Abstract:

Aiming at X80 steel long-distance gas transmission pipeline with volume defects, the mechanical behavior of pipeline with spherical, ellipsoidal and rectangular groove defects is studied by finite element method. Based on the stress condition of the pipeline, the sensitivity analysis of inner and outer wall defects is carried out by using workbench finite element software. The results show that the inner wall defects are more sensitive than the outer wall defects under internal pressure. The stress distribution under different shape volume defects is compared, and the results show that the stress concentration of the pipeline is mainly in the axial part of the pipeline defect, and the stress increases significantly with the increase of the defect depth and axial length. On this basis, the ultimate bearing capacity of X80 pipeline with volume defects under plastic failure criterion is analyzed, and the calculation results are compared with PCORRC calculation method to verify the correctness of the finite element results.

Key words: X80, volumetric defect, long-distance gas transmission pipeline, safety evaluation, finite element model, stress distribution, nonlinear finite element