Studying the Effect of Thermal Shock on Stress Intensity Factor Using FEM

This research concerns with studying the effect of sudden increment in temperature or thermal shock effect on Stress Intensity Factor generated at crack region. The Mechanical Stress Intensity Factor (MSIF) was computed using Finite Element Method technique with the aid of ANSYS software as well as a theoretical methods. The percent of error as a comparison between these results was about (3.18%). Elements used for thermal analysis were plane77, then by using switch element technique from thermal to structural so, elements would be plane82 for structural analysis. A comparison between this value and the values of Thermal Stress Intensity Factor (TSIF) which is generated due to thermal stresses in case of applying a thermal load (thermal shock) had been adopted to know the importance of this effect. So, a coupled field method with the same program, had been used to calculate these values with estimation effect of heat transfer method. The results proved that for an instant temperature difference the effect of steady-state heat transfer method was more than the transient method. Also TSIF for low temperature difference, may exceed the value of MSIF in case of (100 MPa) statical structural applied load without considering the temperature effects.