Finite Element Simulation of a Welding in Pipes: A Sensitivity Analysis

Thermal cycling, high heating rates, high temperature peaks and inter-pass and post weld cooling are parameters that largely affect residual stress generation in and around welds. A multi-pass weld joining two pipes made of different materials is simulated using 2-D axi-symmetric finite element analysis. The proposed methodology for weld simulation incorporates the wefl-known birth of elements technique and follows the prescribed temperature approach for heat input modeling. The effect of various aspects of modeling, on the accuracy of predicted residual strains, is investigated through a series of sensitivity tests, using a 2-D axi-symmetric model. Radiation, creep and heat input model selection, have a significant impact on results, but phase change, convective cooling and pipe contact are not as important. Results are also compared to neutron diffraction measurements obtained from the literature. Welding electrode start/stop effects on predicted residual strains are found to be significant, after a limited 3-D analysis, which justifies further investigation.

OHMS Carsten;  YOUTSOS Anastasius; 

KATSAREAS D.; 

2007-01-04

Springer

JRC33675