An Approach to Robust Fatigue Life Prediction to Be Used in Early Design Stages

Many engineering structures eventually fail through fatigue. Design against fatigue is one of the more important parts of the engineering design process in order to avoid injuries/fatalities, improve sustainability and decrease costs. Design against fatigue is often a complicated and time-consuming process. New, faster, and sufficiently accurate engineering tools are much needed to allow for quick computational estimates as well as robust and risk-minimized engineering solutions. By combining knowledge from the fields of solid mechanics and quality management, such a tool has been developed and is proposed in this paper. By combining easy-to-use tools for robust design and probability design with engineering tools for stress analysis and fatigue analysis, regression equations and response surfaces can be developed to be used for choosing a robust solution. Hence reducing the sensitivity to variation in loads, material characteristics and other noise factors. After a design has been selected, a more detailed analysis can be carried out to validate the solution. Preliminary results from an application of analysis and design of an airplane wheel axle are presented.