Abstract
Consideration has been conducted on the quantitative evaluation of the residual stresses and deformations due to longitudinal welds of a pipe. In the present study, the trapezoid-inherent strain model based on the Green function in a non-stationary thermoelastic problem of a thin cylindrical shell, was newly proposed to estimate the stresses/deformations. The stresses and deformations calculated from the analytical model proposed newly agree well with those measured in the practical longitudinal welds. The parameters controlling the properties of the residual stresses and deformations could be derived analytically by using the above analytical model. The controlling parameters, which it is confirmed experimentally to be successful for evaluating stresses and deformations, are (Tav)x{=Q/2cρπah} and βz{=√a/h·a/l}, where Q, c and ρ are net heat input per unit weld length, specific heat and density, and a, h and l are the mean radius, thickness and length of a cylindrical shell respectively. When the value of the parameter βx is considerably small, both of the residual stresses and deformations are determined by the only parameter (Tav)x.
