Two-parameter Failure Model Improves Time-independent and Time-dependent Failure Predictions

Huddleston, R L

Lawrence Livermore National Laboratory

关键词: Alloys;    Engines;    Steels;    36 Materials Science;    Stainless Steels;   

DOI  :  10.2172/15009772
RP-ID  :  UCRL-TR-202300
RP-ID  :  W-7405-ENG-48
RP-ID  :  15009772

美国|英语

来源: UNT Digital Library

【 摘 要 】

A new analytical model for predicting failure under a generalized, triaxial stress state was developed by the author and initially reported in 1984. The model was validated for predicting failure under elevated-temperature creep-rupture conditions. Biaxial data for three alloy steels, Types 304 and 316 stainless steels and Inconel 600, demonstrated two to three orders of magnitude reduction in the scatter of predicted versus observed creep-rupture times as compared to the classical failure models of Mises, Tresca, and Rankine. In 1990, the new model was incorporated into American Society of Mechanical Engineers (ASME) Code Case N47-29 for design of components operating under creep-rupture conditions. The current report provides additional validation of the model for predicting failure under time-independent conditions and also outlines a methodology for predicting failure under cyclic, time-dependent, creep-fatigue conditions. The later extension of the methodology may have the potential to improve failure predictions there as well. These results are relevant to most design applications, but they have special relevance to high-performance design applications such as components for high-pressure equipment, nuclear reactors, and jet engines.