基于循环冲击加速试验的某O型橡胶密封圈寿命评估方法

目的 快速准确评估温度循环条件下某O型橡胶密封圈的贮存寿命。方法 模拟O型橡胶密封圈真实受压状况，设计专用夹具，在4个应力条件下开展温度循环冲击加速寿命试验，获得密封圈退化数据，分析并获得密封圈伪失效寿命，构建修正Coffin-Manson模型，并利用不同试验条件下得到的伪失效寿命数据对模型进行参数估计，获得Coffin-Manson寿命预估模型，外推常温条件下密封圈的贮存寿命。结果 通过试验表明，指数模型相比对数模型与线性模型能更准确描述密封圈的退化情况，经Coffin-Manson模型评估，该O型橡胶密封圈常温条件下的贮存寿命为6.13 a，与工程经验数据吻合。结论 所提出的基于循环冲击加速试验的O型橡胶密封圈寿命评估方法可以准确评估密封圈的贮存寿命，大大缩短试验周期，节省寿命评估试验时间和成本，为密封器件的寿命评估提供了参考。

Life Evaluation Method of O-type Rubber Seal Ring Based on Cyclic Impact Acceleration Test

The work aims to quickly and accurately evaluate the storage life of O-type rubber seal ring under temperature cycling condition. Special fixtures were designed to simulate the real compression condition of O-type rubber seal ring. The degradation data of seal ring were obtained by temperature cycling impact acceleration life tests under four stress conditions. The false failure life of seal ring was analyzed and obtained. The modified Coffin-Manson model was constructed and the false failure life data obtained under different test conditions were used to estimate the parameters of the model. Then, the Coffin-Manson life prediction model was obtained, and the storage life of seal ring was extrapolated under normal temperature. The test results showed that the exponential model could describe the degradation of the seal ring more accurately than the logarithmic model and the linear model. After evaluated by Coffin-Manson model, the storage life of the O-type rubber seal ring under normal temperature was 6.13 years, which was in accordance with the engineering experience data. The proposed life evaluation method of O-type rubber seal ring based on cyclic impact acceleration test can accurately evaluate the storage life of seal ring, greatly shorten the test cycle, save the time and cost of life evaluation test, and provide reference value for the life evaluation of seal devices.