中文摘要：

维持高水平的管道完整性和可靠性对油气管道工业至关重要。由于各种因素,造成管道失效。其中,管道上的缺陷是导致管道失效的主要原因,而凹陷缺陷又是管道上常见的缺陷类型之一。因此,有必要对管道上的凹陷进行深入的研究。针对油气管道上存在的I型单纯凹陷,分析I型单纯凹陷区域的残余应力与各参数之间的关系。基于疲劳寿命模型,分析凹陷区域的残余应力对管道疲劳寿命的影响。对于新管线的设计和在役管线的维护具有重要意义。

英文摘要：

Maintain a high level of integrity and reliability of pipelines for oil and gas pipeline industry is essential. Due to various reasons, there will lead to the pipeline failure. Among them, pipeline defect is the main reason to the failure of itself. And dent defect is one of the general defect types. Therefore, it is necessary to conduct a further study on pipeline defect. In allusion to type I plain dent existing on oil and gas pipelines, analyzing the relationship between residual stress which is on type I plain dent area and various parameters. Based on fatigue life model, obtaining the influence rule of residual stress on pipehne fatigue life. It is significant for the design of new pipeline and maintenance of in service pipeline.