Application of nonlinear continuum damage model in fatigue modeling of different stress ratio tests

Non-linear cumulative fatigue damage model based oncontinuum damage mechanics (CDM) is considered tomodel the maximum stress - fatigue life for different stressratio. The used model is dependent on the maximum stress,ultimate strength, and the mean stress. A simple relation isobtained to give the fatigue life of the element under cyclicloadings. Its ability to describe all the main features offatigue damage and the ease of its practical use forengineers, are discussed. The material constants of the usedmodel for 7075-T6 alloy are obtained based on twodifferent stress ratios. The CDM model is applied fordifferent stress ratio and S-N curves are obtainednumerically.

Keywords:

Continuum damage mechanics , Fatigue , stressratio , Mean stress , 7075-T6