The study focuses on the flexible thermal connection joint in the active fluid loop of spacecraft, conducting stress, stiffness, and fatigue analysis. A computational model of the flexible thermal connection joint - bellows was established and simplified through ANSYS finite element analysis, analyzing its stress, stiffness, and the stiffness coefficient correction under yield limit. Based on the Miner linear fatigue damage theory and data from the N-code fatigue analysis software library, a fatigue analysis of the bellows was carried out. The results show: the torque corresponding to the yield limit of the bellows is 132.06N, and the corresponding twist angle is 259°; the stiffness coefficient is 1.238 when not considering the effect of the torque arm, and is 1.245 when considering the effect of the torque arm; the fatigue life, fatigue safety factor, and strength safety factor of the bellows under torsional limit without preload force are all in a safe state. However, if a preload force is applied to the bellows, it may lead to an unsafe condition.

Ying Zhou, Dong Liu, Jimin Zhang. Fatigue Life Analysis of Flexible Thermal Connection Joint Bellows in Vacuum Environment for Aerospace Applications. International Journal of Frontiers in Engineering Technology (2023), Vol. 5, Issue 8: 8-19. https://doi.org/10.25236/IJFET.2023.050802.

[1] Jin Jian, Wang Yuning. Analysis of the influence of pipeline layout on the heat dissipation capacity of manned spacecraft radiator [J]. China Space Science and Technology, 2017, 37 (01): 66-74. DOI: 10. 16708/j. cnki. 1000-758X. 2017. 0009

[2] Xu Xianghua, Cheng Xuetao, Liang Xingang. Optimization design of the fluid circuit of the active thermal control system of manned spacecraft [J]. Journal of Astronautics and Astronautics, 2011, 32 (10): 2285-2293

[3] Ning Xianwen, Li Jindong, Wang Yuying, Jiang Fan. Review of Progress in the Construction of New Thermal Control Systems for Chinese Spacecraft [J]. Journal of Aeronautics, 2019, 40 (07): 6-18

[4] Farfan S, Rubio-Gonzalez C, Cervantes-Hernandez T, et al. High cycle fatigue, low cycle fatigue and failure modes of a carburized steel[J]. International journal of fatigue, 2004, 26(6): 673-678. 

[5] Dang-Van K. Macro-micro approach in high-cycle multiaxial fatigue [J]. ASTM Special Technical Publication, 1993, 1191: 120-120. 

[6] McDiarmid D L. A general criterion for high cycle multiaxial fatigue failure [J]. Fatigue & Fracture of Engineering Materials & Structures, 1991, 14(4): 429-453.  

[7] Kong Y S, Omar M Z, Chua L B, et al. Fatigue life prediction of parabolic leaf spring under various road conditions[J]. Engineering Failure Analysis, 2014, 46: 92-103. 

[8] Amzallag C, Gerey J P, Robert J L, et al. Standardization of the rainflow counting method for fatigue analysis[J]. International journal of fatigue, 1994, 16(4): 287-293. 

[9] Liu G, Wang D, Hu Z. Application of the rain-flow counting method in fatigue[C]//2nd International Conference on Electronics, Network and Computer Engineering (ICENCE 2016). Atlantis Press, 2016: 236-240. 

[10] Bishop N W M. The use of frequency domain parameters to predict structural fatigue [D]. University of Warwick, 1988. 

[11] Pitoiset X, Preumont A. Spectral methods for multiaxial random fatigue analysis of metallic structures [J]. International journal of fatigue, 2000, 22(7): 541-550. 

[12] Jiang Y, Yun G J, Zhao L, et al. Experimental design and validation of an accelerated random vibration fatigue testing methodology [J]. Shock and Vibration, 2015. 

[13] Zhou Xinjian, Zhang Songxing. Fatigue Life Analysis of Primary Steel Circular Springs for Rapid Metro Vehicles Based on ANSYS/FE-SAFE [J]. Machine Tool and Hydraulic, 2021, 49 (01): 130-133

[14] Liu Zhipeng, Zhou Jie, Wang Shilong, Wang Sibao, Yang Wenhan. Fatigue Life Prediction of Multi Strand Spiral Springs Based on Finite Element Method [J]. China Mechanical Engineering, 2021, 32 (02): 141-146

[15] Zeng Cheng, Chen Zhongming. Analysis of the fracture problem of the primary spiral steel spring of a certain type of vehicle in Guangzhou Metro [J]. Urban Rail Transit Research, 2018, 21 (09): 145-147. DOI: 10. 16037/j. 1007-869x. 2018. 09. 037

[16] Fan Qinshan. Mechanics of Materials [M]. Beijing: Higher Education Press, 2005: 58-61

[17] Zhang Heping, Xu Wentao, Tang Yunjun, Wu Shaoning, Zhao Muqing. Fatigue Life Prediction of Micro Car Drive Axle Housing [J]. Journal of Wuhan University of Technology (Information and Management Engineering Edition), 2014, 36 (01): 57-60