空间对接机构钢丝绳应力松弛加速退化试验研究

Accelerated Degradation Testing study on Space Docking Mechanism Wire Rope Stress Relaxation

针对空间对接机构在轨工作15年,寿命试验周期长的难题,提出了以温度为加速应力的加速退化试验(ADT)方案,设计了钢丝绳应力松弛测试装置。开展不同温度下的钢丝绳应力松弛试验,并获取寿命特征量数据,用加速退化寿命模型对钢丝绳应力松弛情况进行预测。结果表明:钢丝绳在初始预紧力为3400 N时,可以满足空间对接机构25℃在轨工作20年的需求。并将ADT分析结果与空间对接机构产品存贮9年后的实测值进行对比,表明ADT分析结果与实测数值接近,用ADT分析结果作为对接机构钢丝绳在轨寿命考核评估具有指导意义。

Considering the difficulty of long life testing period as the space docking mechanism works for 15 years in orbit,an accelerated degradation testing scheme which takes temperature as accelerated stress is proposed.A stress relaxation testing equipment for wire rope is designed.The wire rope stress relaxation test is performed at different temperature,and life parameter data is obtained.Finally,the state of the wire rope stress relaxation is predicted by accelerated degradation life model.The analysis result indicates that when the preload of wire rope is 3400 N,the requirement of space docking mechanism working for 15 years in orbit at 25℃is satisfied.The analysis result of the accelerated degradation testing have been compared with the measured value of a space docking mechanism product stored for 9 years on earth,and the comparison result is consistent basically.It is validated that it is instructive assessing wire rope’s life of the space docking mechanism on orbit by accelerated degradation testing analysis result.