某O型密封圈的双参数加速退化规律分析

Regular Pattern of the O-ring’s Two-parameter Accelerated Degradation

目的研究某O型密封圈在温度影响下的退化规律。方法以压缩永久变形率和压缩应力松弛率作为参数,在50、60、70、80℃对某O型密封圈进行恒定应力加速退化试验,根据退化数据建立退化轨迹模型,确定伪失效寿命的分布,结合阿伦尼斯模型外推20℃时某O型密封圈的寿命,并进行可靠性分析。结果某O型密封圈的性能退化过程具有可加速性,它的伪失效寿命服从正态分布。根据压缩永久变形参数外推20℃下、0.9可靠度时,某O型圈的寿命为8.695年,根据压缩应力松弛参数外推的寿命为8.748年,根据双参数不相关的情况外推的寿命为8.655年,3次评估结果较为接近。结论文中使用的试验方法和数据处理方法能有效地评估某O型密封圈的寿命。考虑两个参数不相关情况时,得到的评估结果会小于单参数情况下的评估结果。

Objective To study the regular degradation pattern of O-ring affected by temperature.Methods A constant stress accelerated degradation test was conducted at 50,60,70 and 80℃with compression permanent deformation rate and compressive stress relaxation rate as parameters.On the basic of degraded data,the degenerate trajectory model was built,and the pseudo-failure life distribution was determined.The O-ring’s life at 20℃was predicted and its reliability was analyzed combined with the Arrhenius model.Results The performance degradation process of the O-ring had acceleration property.The pseudo-failure life accords with normal distribution.The estimated life of the O-ring under 0.9 reliability at 20℃was 8.695 years based on compression permanent deformation,while 8.748 years based on compressive stress relaxation rate,and 8.655 year based on the two parameters.These three results were similar.Conclusion The test method and data processing method used in this paper can effectively estimate the O-ring’s life.The result obtained when two parameters are not relevant is less than that when there is only one parameter.