关键词: 多股螺旋弹簧, 有限元方法, 子模型技术, 静态响应, 疲劳寿命预测

Abstract: Aiming at the fatigue failure of SWH springs, the special SWH springs used by UAE companies were introduced as the research object. Firstly, the stress-strain history of the SWH springs was analyzed by finite element simulation, and the stress-strain distribution of the key region was accurately calculated by the sub-model technology. The correctness of the finite element model was verified through static response experiments. The fatigue properties of steel wire material were derived from the tensile test and the Manson model. Finally, the fatigue life of the SWH springs was predicted by combining the stress-strain history and the fatigue life prediction criteria, and the experimental verification was performed. The results show that：when SWH springs are compressed, the maximum stress is located at the outer steel wire of the end position and the outer steel wire is mainly subjected to bending stress, which is consistent with the situation of the fractured outer-layer steel wire at the end of the springs. The errors between the response simulation and the measured value do not exceed 5%; The fatigue life predicted by the SWT criterion is in good agreement with the experimental fatigue life, and the predicted fracture positions are consistent with the actual fracture positions.

Key words: stranded-wire helical(SWH) spring, finite element method, sub-model technology, static response, fatigue life prediction