A FREQUENCY RESPONSE METHOD FOR CALCULATING STRESS INTENSITY FACTORS DUE TO THERMAL STRIPING LOADS

Abstract

Abstract— When incompletely mixed hot and cold fluid streams pass adjacent to the surface of a component or a structure, they can cause thermal fatigue damage. An analytical model, based on linear elastic fracture mechanics and the frequency response method, is presented for the assessment of thermal fatigue damage. Various shapes of surface temperature‐time histories, represented by their power spectral densities, are examined. The model is compared with an alternative method based on the impulse response method and good agreement is found. This kind of thermal fatigue is of particular concern in various types of nuclear reactors and rapid shut‐downs of hot plant. The model proposed is intended as an engineering design tool and has been developed as a computer code known as “TBL”.