Numerical simulation of welding stresses and distortions under consideration of temporal and local changes of strain rate

As a result Of high temperature changing rates in the heat affected zone (HAZ) the elevated strain rates during welding may have a high influence of the yield stresses. Higher yield stresses as a result of high strain rates can be observed in hot tensile tests for several materials. A model has been developed and integrated in a multi-purpose FEA-program (ANSYS(R)) to investigate strain rate effects in numerical welding simulation. The routine calculates the current yield stress as a function of the local strain rates. The influence of the resulting stresses and distortions has been analyzed in comparative numerical welding simulations.