Welding Simulation, Residual Stresses, Component Distortion and Microstructure

© Fraunhofer IWM

FEM calculation of residual stress in a welded pipe in comparison with the residual stress measurement by neutron diffraction method (ND)

For the assessment of the fatigue strength of welded joints a realistic estimation of the damaging effect of welding residual stresses are of fundamental importance. A necessary element is the evaluation of the welding residual stress field and its possible degradation under mechanical loading. By means of validated numerical evidence the influence of residual stresses on the structural integrity may be quantified and the design of fatigue-resistant light-weight components facilitated.

For this purpose we develop suitable material models describing the material behavior during the welding process and the resulting residual stress and distortion field precisely. Whether the residual stress field causes damage depends strongly on its behavior during operation. A stable welding residual stress field can affect the material-related fatigue strength and the service lifetime of components and structures.