多股螺旋弹簧微动磨损机理及失效行为研究

Stranded-wire helical spring is a cylindrical helical spring rolled by a strand, which usually consists of several carbon steel wires. It is a critical part of vibration absorber and reposition component in aero engines, major equipments and automatic weapons, which shows excellent comprehensive performances.However, the serious wear, plastic deformation or break damage of the internal wires will occur when the spring bears fatigue load, which is the most significant reason for spring failure. The spring failure strongly affects the reliability of vibration absorber and reposition component of important equipments. Focusing on the requirement of high reliability and long fatigue life, the fretting wear mechanism and failurebehavior of stranded-wire helical spring are researched. The main research work includes three parts. Firstly, a elliptical torsional fretting model is established based on contact mechanics and the subsurface stresses of torsional fretting contact is calculated through semi-analytical method. Secondly, the running behaviour and the failure mechanism of the spring steel wires under the torsional fretting conditions are systematically researched through fretting experiment and finite-element model. Thirdly, the distribution and development of broken wires in spring and fracture feature of broken wire are obtained after the failure test of stranded-wire helical. Further, the failure mode of spring, fracture mechanism of wire and the influence of fretting wear on fracture are investigated. Finally, the research results are helpful to establish the failure criterion and predict the fatigue life of stranded wire helical, providing comprehensive theoretical and technical support for improving the reliability of vibration absorber and reposition component of relevant equipment.

由多股钢丝卷制而成的多股螺旋弹簧（简称多股簧）广泛应用于航空发动机、重型装备和自动武器的减振和复位装置，具有优良的减振和复位效果。但多股簧在疲劳载荷下会产生以弹簧内部钢丝磨损、塑性变形和断裂破坏为典型特征的失效现象，严重影响相关装备减振和复位系统可靠性。本项目针对多股簧高可靠性、长寿命等要求，着重研究多股簧微动磨损机理及失效行为，主要内容包括：1) 建立钢丝在椭圆接触下扭动微动模型，开发基于半解析法的钢丝下表面应力求解算法。2) 结合钢丝扭动微动磨损实验和有限元仿真，系统研究不同试验工况下多股簧钢丝扭动微动运行行为和磨损机理。3) 进行多股簧失效试验，根据多股簧内部钢丝断丝分布与发展规律和钢丝断口形貌，探讨多股簧的失效形式和钢丝断裂机理及微动磨损在钢丝断裂中的影响机制。研究成果有助于建立相应的多股簧失效准则并预测其工作寿命，为提升相关装备减振和复位装置的可靠性提供理论支撑和技术保障。

多股钢丝卷制而成的多股螺旋弹簧（简称多股簧）广泛应用于航空发动机、重型装备和自动武器的减振和复位装置，具有优良的减振和复位效果。但多股簧在疲劳载荷下会产生以弹簧内部钢丝磨损、塑性变形和断裂破坏为典型特征的失效现象，严重影响相关装备减振和复位系统可靠性。本项目针对多股簧高可靠性、长寿命等要求，着重研究多股簧微动磨损机理及失效行为，主要内容包括：1) 建立钢丝在椭圆接触下扭动微动模型，开发基于半解析法的钢丝下表面应力求解算法。2) 结合钢丝扭动微动磨损实验和有限元仿真，系统研究不同试验工况下多股簧钢丝扭动微动运行行为和磨损机理。3) 进行多股簧失效试验，根据多股簧内部钢丝断丝分布与发展规律和钢丝断口形貌，探讨多股簧的失效形式和钢丝断裂机理及微动磨损在钢丝断裂中的影响机制。. 课题基于压缩和拉伸两种多股螺旋弹簧的曲线公式，基于微分几何公式推导了并研究了相关的微分几何参数。在此基础上分析了多股螺旋弹簧的应力应变特性，包括多股螺旋弹簧内部二次螺旋线钢丝的曲率和挠率的变化。本课题还研究得到了更符合实际的表面切向力、扭矩与扭转角的表达式。分别计算扭矩和法向接触力下的应力分布，然后综合计算可以得到von Mises 应力。最后计算了循环载荷下的扭矩与旋转角度变化关系，为后续研究计算循环载荷的表层下应力分布提供理论基础，为后续多股簧的疲劳寿命分析提供了重要的理论基础。研究结果为相关装备减振和复位装置的可靠性的提升提供理论支撑和技术保障，对提升我国自动武器和重大装备减震吸振系统的服役性能具有重要意义。研究成果有助于建立相应的多股簧失效准则并预测其工作寿命，为提升相关装备减振和复位装置的可靠性提供理论支撑和技术保障。