A stochastic deterioration process for time-dependent reliability analysis

The paper presents a stochastic gamma process model to account for both population (i.e., sampling) and temporal variability associated with a degradation process that typically increases the probability of failure with the aging of a structure. The proposed method is more versatile than the random-variable degradation rate model commonly used in the structural reliability literature. The reason being that the random rate model cannot capture temporal variability associated with evolution of degradation. The paper also describes two methods for estimating parameters of the gamma process to facilitate its practical engineering applications.