Reliability based strength/fatigue design criteria

Laboratory testing is a critical step in the development of vehicle components or systems. It allows the design engineer to evaluate the design early in the reliability development phase. A good lab test will shorten the product development cycles and minimizes cost and part failures at the proving ground (PG) testing before the vehicle volume production. In this paper, reliability-based design criteria for vehicle components are demonstrated. The methodology includes: (1) the design load (strength or capacity) of the component requirement; and (2) the lab fatigue life test bogey with constant amplitude loading. Major considerations on laboratory test and PG test procedures are also discussed to the development of a high mileage reliability component or system. The applicability of the reliability-based strength/fatigue design criteria for the design of an axle shaft is demonstrated.