This study focuses on the thermal buckling analysis of a confined noncircular pipeline with an oval inverted arch subjected to thermal loads. A trigonometric formula is employed to illustrate the radial inward deflection of the pipeline resulting from the rigid confinement of the surrounding medium (soils/rocks). The governing equations are derived by integrating the classical shell theory with energy criteria. These equations are solved to obtain the temperature–displacement equilibrium paths and critical temperature variations. Furthermore, a comprehensive comparison is conducted to validate the accuracy of the proposed computational method. This favourable alignment with other available solutions substantiates the effectiveness of this investigation. Finally, the impacts of varying central angles, ovalities, and thickness-to-radius ratios on the thermal stability of a noncircular pipeline with an oval inverted arch are analysed. These conclusions indicate that an increased central angle and ovality significantly affect the thermal stability of the system.

中文翻译：

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椭圆倒拱约束非圆形加热管道热屈曲性能计算方法

本研究重点研究了受热载荷的椭圆形倒拱受压非圆形管道的热屈曲分析。采用三角公式来说明由于周围介质（土壤/岩石）的刚性约束而导致的管道径向向内挠度。控制方程是通过将经典壳理论与能量准则相结合而得出的。求解这些方程以获得温度-位移平衡路径和临界温度变化。此外，还进行了全面的比较，以验证所提计算方法的准确性。这种与其他可用解决方案的有利一致性证实了这项调查的有效性。最后，分析了不同中心角、椭圆和厚半径比对椭圆倒拱非圆形管道热稳定性的影响。这些结论表明，中心角和椭圆度的增加会显着影响系统的热稳定性。