A Comparison of Life Prediction Methodologies for Titanium Matrix Composites Subjected to Thermomechanical Fatigue

Download or read book A Comparison of Life Prediction Methodologies for Titanium Matrix Composites Subjected to Thermomechanical Fatigue written by Calcaterra, JR. and published by . This book was released on 1997 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several methodologies have been developed to predict the lives of titanium matrix composites (TMCs) subjected to thermomechanical fatigue (TMF). This paper reviews and compares five life prediction models developed at NASA-LaRC, Wright Laboratories, and Clarkson University. The models developed at NASA-LaRC and Clarkson University are based on a single parameter, the fiber stress in the load-carrying, or 0°, direction. The two other models, both developed at Wright Labs, are multi-parameter models. These can account for long-term damage, which is beyond the scope of the single-parameter models, but this benefit is offset by the additional complexity of the methodologies. Each of the methodologies was used to model data generated at NASA-LeRC, Wright Labs, and Georgia Tech for the SCS-6/Timetal 21-S material system. Viscoply, a micromechanical stress analysis code, was used to determine the constituent stress state for each test and was used for each model to maintain consistency. The predictive capabilities of the models are compared, and the ability of each model to accurately predict the responses of tests dominated by differing damage mechanisms is addressed.