Reliability Assessment of Spherical Plain Bearing Based on an Independent Incremental Process

To assess the reliability of spherical plain bearing (SPB), an independent incremental process-based degradation model is proposed based on the failure mode analysis. Motivated by the wear data of SPB, the proposed degradation model includes two time transformed functions to describe the stochastic wear failure process. Among that, a linear time transformed function and a quadratic time transformed function are used to represent the degradation trend and variance terms respectively, which can remedy the limitation of the traditional Wiener process-based model that has the same time transformed function in the mean and variance terms. Then the failure time distribution (FTD), the FTD percentiles and the mean time to failures (MTTF) are given based on the proposed model. The maximum-likelihood estimation method is used to estimate the unknown parameters. Finally, the life test data of SPB is used to illustrate the effectiveness of the proposed model in reliability assessment of SPB.