【摘要】 多股螺旋弹簧广泛应用在枪械武器发射系统、潜艇/航天发动机等国防装备之中，但目前对多股簧疲劳失效分析工作十分有限。某圆柱压缩多股簧在寿命试验期间发生断裂失效，采用断口分析、金相检验、硬度测试、有限元仿真等方式对多股簧的断裂原因进行分析；钢丝表面的拉拔条纹与外层钢丝间的接触损伤表面缺陷共同引起应力集中，导致了疲劳裂纹萌生，最终多股簧断裂失效。设计时，在刚度允许的范围内可适当增加钢索捻距，减小钢丝间接触损伤，从而提高多股簧疲劳寿命。更多还原

【Abstract】 The stranded wire helical spring is widely used in weapon launch system,submarine/aerospace engine and other national defense equipment,but the work about the fatigue failure analysis of stranded wire helical spring is limited. A cylindrical compression stranded wire helical spring broke during the life test. Fracture analysis,physical and chemical test and finite element simulation were used to analyze the fracture cause of stranded wire helical spring. The drawing fringe on the wire surface and the contact damage surface defect between the outer wires together cause the stress concentration,which leads to the initiation of fatigue crack,and finally the stranded wire spring fracture.During the design,the twist distance can be appropriately increased within the allowable range of rigidity,so as to reduce the contact damage between wires and increase the fatigue life of stranded wire helical spring.更多还原