Simplified evaluation guideline for thermal fatigue damage due to random fluctuation of fluid temperature

Okajima, Satoshi*; Honda, Kei*; Sakai, Shinsuke*; Izumi, Satoshi*; Oishi, Kunio*; Kasahara, Naoto

It is well known that fatigue damage accumulates around T-junctions of piping system where two kinds of fluid with different temperatures are mixed. Kasahara et al. have proposed the thermal fatigue evaluation method based on power spectrum density (PSD). However, this method is too complex to practical use in the design stage. In this paper, a simplified damage evaluation guideline is proposed based on the Kasahara et al. method. The damage evaluation procedure from stress PSD is simplified in this guideline.