Multiple Load Input Sensitivity Analysis Technique for Finite Element-Based Durability Evaluation

A technique to determine which loads or combination of loads that contribute to the fatigue damage of a component is proposed. Knowing critical loads allows a designer the opportunity to better optimize designs. This information also helps accelerate durability evaluation procedures (both analytical and laboratory based). The technique involves the use of a computer-based FEA method incorporating conventional fatigue life prediction algorithms to assess component durability on an element-by-element basis. After a global fatigue analysis of the entire component, the critical element(s) are identified. A statistical approach, based on a factorial design of experiments, is then applied to assess the effect of varying combinations of component input loads on the predicted durability of these elements. This approach provides a methodology for keeping computational time to a minimum whilst developing a comprehensive understanding of the behavior of the critical areas. The emphasis is a practical design technique.