Experimental study of produced thermal stresses in thin arc welded plates: application of constructal theory in welding paths

摘要

In the present investigation, the basics of constructal theory are used to suggest new welding paths in order to have better heat distributions which will reduce residual stresses in weldments. Aluminum plates have been experimentally welded with a GTA welding instrument. The produced thermal stresses in weldments are measured by X-ray diffraction (XRD) method. Doing so, the experiments are qualitative measurements of residual stresses at different points of weldments. The analysis is based on the comparison of the produced residual stresses in different welding models which have received a fixed amount of heat input during welding. In order to have a tool for further comparison, a numerical modeling is also developed which proved that the shape of experimental residual stress distribution has a good agreement with the results of the presented numerical simulation. A reference point, through which an almost equal amount of input heat is passing, is considered to make the comparison between different models more meaningful. Finally, the amount of residual stress at various points, in different welding models, showed that the suggested constructal welding paths resulted in less residual stresses in weldments. Furthermore, the effect of welding sequences in the amount of generated residual stresses confirmed the previous investigations.