Residual strength degradation of graphite under thermal shock fatigue

The residual strength degradation behavior of graphite under thermal fatigue was investigated experimentally via thermal shock quench test. Fatigue damage models were used to predict the residual strength curve. Cyclic thermal stress was determined by the finite element method. The effect of graphite microstructure defects on the increase of stress was calculated via an image processing technique and microstructure modeling. Results of different fatigue models were validated by various temperature differences experiments. Predicted residual strength was compared with the experimental data and the best model for predicting residual strength under thermal fatigue was determined for graphite.

► Extending the use of progressive damage models to thermal problem & selecting best model for thermal fatigue of graphite. ► Constant parameter of best residual strength model under thermal fatigue was determined for graphite. ► The effect of microstructure defects on thermal stress was assumed by using the image processing technique in this paper.