The influence of welding process parameters on residual stresses by means of coupled thermo-mechanical simulation

摘要

To achieve an accurate lifetime assessment based on welded joints, the value of the effective notch stress by means of local approaches has to be determined. Moreover, detailed knowledge of the local material properties at the complex thermo-mechanical welding process must be available. Hence, a special challenge in the knowledge of local conditions must be performed. The impact of the welding process, e.g., by change of the heat-affected-zone, conducts the local residual stress distribution as well as the restraining boundary condition. The significance of the specimen clamping condition was shown by strain gauge measurements. The need of a local thermo-mechanical coupled simulation model is given especially in the case of strain-based interacting weld seams. The size and shape of the heat-affected-zone was verified by metallographic investigations. Finally, a fatigue life calculation based on the structural stress approach was done.