If I understand your question correctly, the stress from the thermal shock is the modulus of the material times the temperature times the coefficient of thermal expansion. As long as the stress is less than the critical stress intensity K divided by 2.5 divided by the square root of the crack depth then the crack will not propogate.Summary:: the stress strain relation
If i have a thermal shock in a thermo-elastic material with crack mode I propagated ? what are the stress-strain relations in this case? or what is the factor K relation? "sorry if the question is not true, but i hope you understood what i mean"