基于恒定应力加速退化试验的某引信用O型橡胶密封圈可靠性评估

Reliability Evaluation of the O-type Rubber Sealing Ring for Fuse Based on Constant Stress Accelerated Degradation Testing

为了快速评估某引信用O型橡胶密封圈(简称O型圈)的可靠性,根据其安装方式设计模拟夹具,依据橡胶材料的热老化机理,以压缩永久变形率作为老化参数,在50℃、60℃、70℃和80℃4个温度下对32个O型圈进行恒定应力加速退化试验(简称恒加退化试验)。统计分析结果表明,该O型圈的老化过程具有加速性,对其开展加速退化试验是可行的。为分析加速退化数据的有效性,开展135 d的O型圈储存过程模拟试验,利用加速退化数据外推模拟试验环境下O型圈的老化程度。将外推结果与模拟试验结果进行对比,结果表明外推误差较小,本次加速退化试验所得数据是有效的。给出O型圈的可靠度在变环境温度下的推算方法,并依据试验数据给出推算结果。

In order to rapidly assess the reliability of the O-type rubber sealing ring for a fuse （or O-ring for short）, simulation fixture for the O-ring is designed according to its way to install and a constant stress accelerated degradation testing （or CSADT for short） for 32 O-rings is conducted at 50 ℃, 60 ℃, 70 ℃ and 80 ℃, four temperatures, which is based on the thermal aging mechanism of rubber materials, and takes the compression permanent deformation rate of the O-ring. The results of the statistical analysis of the test data indicate that the ageing process of the O-ring has acceleration property, and it is feasible for the O-ring to conduct accelerated degradation testing. In order to analyze the availability of the accelerated degradation data, a simulation test simulating the storage process of the O-ring is conducted for 135 days, and the deterioration of the o-ring under the environment of the simulation test is calculated by using the accelerated degradation data. The extrapolated result is compared with the simulation test result, and the comparison result shows that the extrapolated result’s error is small and the accelerated degradation data is available. The method to calculate the reliability of the O-ring in changing temperatures is given, and calculation result is given according to the test data.