关键词: 系统可靠性；概率预测；共因失效；相关性

Abstract:

The generating and coupling mechanism of common cause failures was studied based on load-strength interference theory and the regularity of the common load giving rise to element failure dependency whereas strengths of components were independent was brought to light. Establishing the relationship among the common load variance, component strength variance and component failure dependency by correlation coefficient, an un-empirical model for probability prediction of common cause failures was derived. Considering the facts that low-order failure data being known and distributed functions of common load and component strength being unknown, a practical method for common cause failures probability assessment was put forward. Different from the conventional model, the new model and method embody the inherent mechanism of common cause failures with overcoming shortages of depending field data or subjective experience too much, which gives a new path for risk data analysis, failure probability prediction and reliability design of redundant systems.

Key words: system reliability, probability prediction, common cause failure, dependence