Failure rate behavior of components subjected to random stresses

This paper presents a theoretical study of the failure rate behavior of components subjected to random environmental stresses. Three kinds of stresses are considered: point, alternating, diffused. The concept that the component could memorize the stress is introduced. Diverse types of stress action can thus be defined: instantaneous, cumulative, recovering. Two classes of stochastic models are proposed, which express the effect of stress to the lifetime of the component. Several examples for which the resulting failure rate has an explicit expression, are presented. In most of these examples, the failure rate converges rapidly to a constant, that confirms a conjecture frequently made by the engineers.