Assessment of Error and Pressure Influence on Total Equivalent Stress Amplitude Calculation by WRC107

Bulletin WRC107 is most commonly used in attachment design, but still some uncertainties make it difficult to ensure safety in recent use. Two problems in fatigue evaluation were addressed here, first the bulletin is based on shell theory and some other assumption, and for various condition the calculation error is unknown; second pressure is not considered in calculation. To the first problem, an assessment was performed by comparing the total equivalent stress results of WRC107 and of finite element method (FEM). To the second problem, a method from Chinese standard HG20582-1998 Specification for Stress Calculation of Steel Chemical Vessels (HG method) was introduced as a supplement, and the reliability was studied. The results show that, total equivalent stress amplitude calculated by WRC107 may be underestimated, and its error mainly depends on parameters β and γ. Complemented by HG method, WRC107 could be used in calculation of shell under pressure and external loading.