Abstract
Angular distortions and mis-fitted ones often occur in joints of a large pressure vessel by errors and deformations in assembling parts and welding those. When internal pressure is loaded to a vessel with distortions, a tensile strain is considerably concentrated at the distorted joints. Such a strain concentration usually affects the fatigue strength and the stress corrosion. cracking (SCC) of materials. It is therefore very important to be suitably determined for allowable amount of distortions in order to predict the remained life of the pressure vessel. The present paper shows the difference of the stress-strain behavior in the case of concave distortion and in that of convex one. Even if the relative amount of distortion is very small as compared with the radius of the pressure vessel, an expression for the distortion part based on initial spherical surface is indispensable for an accurate estimation of the strain concentration.
