The relationship between type Ⅱ plain dent damage degree and dent depth on varied internal pressure

摘要

Dent is a common defect of oil and gas pipelines and the assessment on dented pipelines is carried out according to major international standards and specifications with dent depth as the evaluation criteria.However, such evaluation criteria based on depth does not take the impact of other parameters (for instance, the internal pressure of pipeline) on the evaluation result into consideration; as a result, many dented pipelines that meet the specifications still lose their efficacy.In allusion to II-type plain dent existing on the oil and gas pipelines, the influence rule of the internal pressure of pipeline changes on the damage degree of dented pipelines is obtained on the basis of Oyane's Ductile Fracture Criterion and by adopting the finite element numerical method.