帅健, 孔令圳. 高钢级管道环焊缝应变能力评价[J]. 油气储运, 2017, 36(12): 1368-1373. DOI: 10.6047/j.issn.1000-8241.2017.12.004
引用本文: 帅健, 孔令圳. 高钢级管道环焊缝应变能力评价[J]. 油气储运, 2017, 36(12): 1368-1373. DOI: 10.6047/j.issn.1000-8241.2017.12.004
SHUAI Jian, KONG Lingzhen. Evaluation on strain capacity of girth welds in high-grade pipelines[J]. Oil & Gas Storage and Transportation, 2017, 36(12): 1368-1373. DOI: 10.6047/j.issn.1000-8241.2017.12.004
Citation: SHUAI Jian, KONG Lingzhen. Evaluation on strain capacity of girth welds in high-grade pipelines[J]. Oil & Gas Storage and Transportation, 2017, 36(12): 1368-1373. DOI: 10.6047/j.issn.1000-8241.2017.12.004

高钢级管道环焊缝应变能力评价

Evaluation on strain capacity of girth welds in high-grade pipelines

  • 摘要: 为了评价高钢级管道环焊缝的应变能力,建立了基于材料损伤理论的管道环焊缝有限元模型。通过优化裂纹尖端网格尺寸,准确模拟了裂纹尖端的应力分布及撕裂过程。采用屈服强度和均匀延伸率表征高钢级管道的材料特性,计算并分析了管道环焊缝的裂纹驱动力曲线,建立了裂纹扩展失稳准则和材料断裂韧性准则两种失效判据,研究了管道材料性能、裂纹长度及内压对裂纹驱动力的影响,定量分析了这些影响因素与管道应变能力之间的关系。结果表明:较之内压,裂纹长度对管道应变能力影响较大,材料均匀延伸率较屈服强度对管道的应变能力影响更大。针对基于应变设计的管道,建议对环焊缝提出均匀延伸率等塑性容量指标的要求,从而更好地为基于应变的高钢级管道的设计和评价提供技术依据。

     

    Abstract: In this paper, the finite element model of pipeline girth weld based on material damage theory was built to evaluate the strain capacity of girth welds in high-grade pipelines. The stress distribution and tearing process at the crack tip were accurately simulated by optimizing the grid size at the crack tip. The material properties of high-grade pipeline were characterized by using yield strength and uniform elongation. The crack driving force curve of the pipeline girth weld was calculated and analyzed. Two failure criteria were developed, i.e., crack growth instability criterion and material fracture toughness criterion. The effects of pipe material performance, crack length and internal pressure on the crack driving force were investigated. And the relationships between these influential factors and pipeline strain capacity were quantitatively analyzed. It is shown that crack length has more effect on the pipeline strain capacity than the inner pressure, and the uniform elongation of pipeline material has more effect on crack growth driving force than the yield strength. It is recommended that in the pipelines designed on the basis of strain, girth welds should satisfy the requirements of plastic capacity indicators (e.g. uniform elongation). The research results provide the technical basis for the design and evaluation of the strain based high-grade pipelines.

     

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