Mechanical Engineering Faculty Research

Title

Predicting Crack Growth under Thermo-mechanical Cycling

Document Type

Article

Publication Date

11-1-1989

Abstract

Load-controlled tests were conducted on Inconel 718 under thermo-mechanical fatigue (TMF) to evaluate crack growth rate as a function of phase angle between load and temperature. A model is developed to predict TMF crack growth rates based solely on isothermal data. The model uses a linear summation concept based on contributions to crack growth of the two dominant mechanisms which are active at the minimum and maximum temperature of the cycle: mechanical fatigue and environmentally assisted crack growth. It was found that damage which contributes significantly to crack growth occurs only during the increasing load portion of a TMF cycle and only while the time-dependent contribution is an increasing function. A discussion of the dominant mechanisms and a comprehensive review of the literature in TMF crack growth is presented. Applicability of the modeling concepts to other materials is discussed.

Publication Title

International Journal of Fatigue

Volume

41

Issue

3

First Page

157

Last Page

176