Simulation des thermischen Verhaltens beim Reibrührschweißen zur Vorhersage von Eigenspannungen

Abstract

Using a transient thermal finite element analysis, the thermal behavior during friction stir welding (FSW) of aluminum sheets for aerospace applications was calculated. The thermal behavior during the FSW process is of interest for all aspects of distortion engineering or microstructural interpretations for material design. In the presented approach only the measured temperature history of the welding tool, the thermo mechanical material properties and thermal contact properties have to be known. Since the calculated time depending temperature distribution agrees very well with experimentally measured temperatures at seven different locations during a FSW experiment, it is concluded that the model accurately predicts the thermal history during welding. In addition, a first attempt to calculate the residual stresses and the sheet distortions caused by these residual stresses is presented and compared to experimental results. Although the calculated values of the distortion are too low compared to experimental results, the approach gives a first impression on the origin of the distortion and will be pursued in further investigations.