Abstract In this study, a NC35 tool joint with double shoulder is considered as the research object and studied by finite element method (FEM) using nonlinear thermo-mechanical coupled model and implicit & explicit conversion method. Von mises stress field, temperature field, contact stress, and ultimate working torque of tool joint under different axial loads at high temperatures are calculated and compared with those at normal atmospheric temperature. High temperature doesn't change the stress and contact stress distribution under make-up torque condition but reduces the value of stress and contact stress due to material properties decline. Ultimate working torque decreases with the increase of temperature under the same axial load. Coupled influence of axial load and temperature on shoulder contact state is analyzed. Furthermore, failure modes of tool joint under different temperatures and axial loads are discussed. According to the results of calculation, a guiding diagram considering safety factor is presented which can provide a safe operating range at normal atmospheric temperature and high temperature. It can help engineers choose appropriate operating parameters under different conditions.

中文翻译：

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高温对钻杆接头强度、接触应力和极限扭矩影响的非线性热力耦合分析

摘要 本研究以NC35双台肩钻杆接头为研究对象，采用非线性热力耦合模型和显式转换方法，采用有限元法(FEM)进行研究。计算了高温下不同轴向载荷下钻杆接头的Von mises应力场、温度场、接触应力和极限工作扭矩，并与常温下进行比较。高温不会改变上紧扭矩条件下的应力和接触应力分布，但会因材料性能下降而降低应力和接触应力值。在相同的轴向载荷下，极限工作扭矩随着温度的升高而减小。分析了轴向载荷和温度对台肩接触状态的耦合影响。此外，讨论了不同温度和轴向载荷下钻杆接头的失效模式。根据计算结果，给出了考虑安全系数的指导图，可以提供在常温和高温下的安全运行范围。它可以帮助工程师在不同条件下选择合适的工作参数。