Determination of Residual Stress Profiles of Pipe Girth Weld Using a Unified Parametric Function Form

In this paper we present an improved analysis of residual stress data of a pipe girth weld by applying the developed heuristic method to one set of high-quality residual stress measurement data. The through-thickness residual stress is expressed as a parametric function form which is a combination of three stress components: membrane, bending and self-equilibrating. This parametric function form provides not only a clear physical basis for the residual stress profile, but is also closely related to two important governing parameters, i.e. the pipe geometry and the welding heat input. The residual stress profiles obtained are also compared with results predicted by the Bayesian method as well as the profiles from the UK R6 procedure and the US API 579 code.