Reliability Evaluation Method of Buried Natural Gas Pipeline under Random Stress

Abstract

For random degradation equipment such as buried natural gas pipeline with cracks, the existing research methods rely more on failure mechanism analysis. However, the construction of failure mechanism models is difficult and complex and has limitations in its use. To overcome these shortcomings, this paper proposes a method based on a nonlinear Wiener degradation model considering the influence of stress. In this method, the effect of stress on the pipe is regarded as a random variable to affect the degradation rate of the pipe, and individual variability is also considered to obtain more accurate reliability assessment results from the nonlinear degradation model. The function of residual life probability density is determined at the first reach failure time. Then, for the degraded small samples, the maximum likelihood estimation is used to estimate the parameters and determine the distribution and reliability functions. The results based on crack data demonstrate the accuracy and validity of the proposed method.