BOUNDARY-ELEMENT ANALYSIS OF THERMAL-STRESS INTENSITY FACTORS FOR CUSP CRACK IN TRANSIENT STATE

The boundary element method is applied to determine thermal stress intensity factors for a cusp crack in a transient state. In the steady temperature field, numerical values of thermal stress intensity factors for a Griffith crack and a symmetric lip cusp crack in a finite body are in good agreement within +/- 5% when compared with the previous solutions. In a transient state, the numerical values of thermal stress intensity factors for the Griffith crack are also in good agreement when compared with the previous solutions. In both steady and transient states, those for the symmetric lip cusp crack with the crack surface insulated or fixed to a constant temperature are calculated with various effective crack lengths, configuration parameters and uniform heat flow angles. The variations of the thermal boundary conditions of the crack surface have a great effect on stress intensity factors. The signs on the values of thermal stress intensity factors can be changed with time variation.