Prediction of Failure in Ductile Machine Elements Operating at Elevated Temperatures

Abstract

This paper provides the designer with formulations and data so that he can more confidently design a ductile machine element, operating at elevated temperatures, by employing obtainable strength data at those temperatures. The paper begins by taking a panoramic view of the state of the art regarding a procedure for designing such elements, under such conditions, on the basis of stress vs. strength. Then, the paper combines the basic principle of the distortion-energy theory of failure, long recognized as the best theory of failure for ductile materials by well documented experiments, with thermodynamic behavioral and mechanical properties. This combination and accompanying study result in formulation, information and data so that the validity of the aforementioned design practice is given a sound theoretical basis. Specific applications are taken for various categories of steel with very good agreement between the theory and experimental data. However, with necessary data, the procedure can be applied to other ductile metals as well.