Structural response function approach for evaluation of thermal striping phenomena Original Research Article

A rational analysis method for thermal stress induced by fluid temperature fluctuation is developed, by utilizing frequency response characteristics of structures. High frequency components of temperature fluctuation are attenuated during a transfer process from fluid to structures. Low frequency components hardly induce thermal stress, since temperature homogenization in structures. Based on investigations of the frequency response mechanism, a frequency response function of structures was derived, which can predict stress amplitudes on structural surfaces from fluid temperature amplitudes and frequencies. It is formulated by multiplication of the effective heat transfer and the effective thermal stress functions. The frequency response function was applied to fatigue analysis of nuclear components, and clarified relation of fatigue damage to thermal hydraulic and structural design parameters.