具有指数衰减振荡型概率密度变化规律的产品寿命分布模型

Life Distribution Model of Products with Variable Probability Density of Exponential Attenuation Oscillation

传统的机械产品可靠性模型大多忽略了周期性故障引起的概率密度的振荡特征,从而影响了模型的精度。在传统寿命模型的基础上,构建指数衰减振荡分布的可靠性模型及相应的可靠度、失效率以及平均寿命计算模型,并研究衰减系数、振荡幅值和振荡角频率等参数对概率分布特征的影响。运用建立的概率分布模型对某型叉车搭载的液力自动变速箱故障时间数据进行拟合,并与指数分布模型、三参数威布尔模型和"浴盆曲线"模型拟合结果进行对比。对比结果表明,建立的指数衰减振荡分布模型能够较好地描述该液力变速箱的无故障工作时间概率分布特征,并且采用该模型可以获得较小的拟合均方根误差。

Most of traditional reliability models for traditional mechanical products ignore the oscillation characteristics of probability density caused by periodic faults,which affects the accuracy of the models.The reliability model of the exponential attenuation oscillation distribution and the corresponding reliability,failure rate,and average life calculation models are constructed on the basis of the traditional life model.Then,the effect of parameters including the attenuation coefficient,oscillation amplitude,oscillation angular frequency on the probability distribution characteristics is studied.As an example,the failure time data of automatic transmission of a forklift truck are fitted with the proposed probability distribution model.And the fitting results are compared with those of the exponential distribution model,the three-parameter Weibull model and the bathtub-shaped curve model.The results show that the probability model can better describe the probability distribution characteristics of the fault-free working time of automatic transmission,and the model can obtain a smaller root mean square error.