Abstract For damaged submarine pipelines, interference fit is necessary for the mechanical connector repair. The ovality of pipelines resulting from the fabrication errors is easy to increase the failure risk during the fit process. In order to ensure the construction safety, it is necessary to judge whether the repair process may be affected by the strength damage in advance. Since the interference joint with ovality is a complex nonlinear contact problem, there is no theoretical model for reference at present. Reasonable and verified numerical simulation has been proved to be a convenient and feasible solution. In this paper, the finite element (FE) software ANSYS was used to analyze the contact characteristics of the pipeline coupled with the theory of combined thick-wall cylinder. The influences of the equivalent interference and pipeline ovality on the maximum effective stress of the pipeline were quantitatively characterized, and the corresponding correlation model was fitted. The results show that the contact stress of pipeline is closely related to the equivalent interference, the ovality hardly effects it but has a significant effect on the uniformity of the contact stress distribution on the interference surface. Furthermore, according to the theoretical solution, the prediction model of the equivalent stress of pipeline is deduced with an introduced ovality stress concentration coefficient. The prediction model can effectively evaluate the strength of the submarine pipeline after interference repair. The rationality and practicability of this method are validated by simulation analysis of a practical engineering project.

中文翻译：

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椭圆形海底管道与机械接头干涉接头强度分析

摘要 对于损坏的海底管道，机械接头修复需要过盈配合。由于制造错误导致的管道椭圆度容易增加装配过程中的失败风险。为保证施工安全，需提前判断修复过程是否可能受到强度破坏的影响。由于具有椭圆度的干涉接头是一个复杂的非线性接触问题，目前还没有可供参考的理论模型。合理且经过验证的数值模拟已被证明是一种方便可行的解决方案。本文采用有限元（FE）软件ANSYS，结合组合厚壁圆柱体理论，对管道的接触特性进行分析。定量表征了等效过盈量和管道椭圆度对管道最大有效应力的影响，并拟合了相应的相关模型。结果表明，管道接触应力与等效过盈量密切相关，椭圆度对其影响不大，但对过盈面接触应力分布的均匀性有显着影响。此外，根据理论解，引入椭圆度应力集中系数，推导出管道等效应力预测模型。该预测模型可以有效评估干扰修复后海底管道的强度。