An explicit integral expression for the stress intensity factor of a semi-elliptic surface crack subjected to thermal transient loading

An explicit integral expression for the stress intensity factor of a semi-e lliptic surface crack in a plate subjected to thermal transient loading was developed. The stress intensity factor of a semi-elliptic surface crack in a plate, which is exposed to a step change of fluid temperature, was calcu lated on the basis of the weight function method. The change of the stress intensity factor for a semi-elliptic surface crack subjected to an arbitrar y change of the boundary fluid temperature was obtained by Duhamel integrat ion for the product of the step function result and the time varying fluid temperature. The result obtained by the present method has shown good agree ment with those obtained by the influence function method. As a practical a pplication, a parametric analysis was performed for the crack behavior Juri ng the emergency cool down of reactor coolant in the reactor pressure vesse l. Also, the present expression can be effectively applied to the simulatio n of fatigue crack growth of a semi-elliptic surface crack subjected to var ious thermal transient loading. (C) 1999 Elsevier Science Ltd. All rights r eserved.