DYNAMIC RELIABILITY MODELING OF SYSTEMS WITH COMMON CAUSE FAILURE UNDER RANDOM LOAD

This paper presents a new method for developing the dynamic reliability model of systems, in which reliability and hazard rate of systems are expressed as functions of load, strength and time. First, reliability models of systems with common cause failure are developed by applying the load-strength interference model, and the cumulative distribution function and the probability density function of strength for different systems are derived. Reliability models of systems under repeated random load are developed. Then, the loading process is described as a Poisson stochastic process, the dynamic reliability models of systems without strength degeneration and those with strength degeneration are derived. Finally, the relationship between reliability and time, and the hazard rate of systems, are discussed. The results show that even if strength does not degenerate, the reliability of systems decreases over time, and the hazard rate of systems decreases over time, too. When strength degenerates, the reliability of systems decreases over time more rapidly and the hazard rate curves of systems are bathtub-shaped The models proposed can be applied to determine the duration of a trial run, the reliable operation life and the maintenance schedule. It is helpful for the life cycle management of systems.