Residual Stresses Determination in Welding Processes Using Plane Plates Made of Photoelastic Material

The purpose of this paper was determination of residual stresses from welding processes in polycarbonate plane plates, medium to fine thickness. Experimental technique of plane photoelasticity was used for stress analysis. Stress level was determined according welding procedures and parameters established for each one of those procedures: height of the air flow jet, compressed air flow, temperature, welding sequence and sense of welding passes. It was obtained, a mapping of stresses and at the same time it was verified how welding situation affects stress state after welding process. Welding of medium to fine thickness plates results in large residual deformation next to the welding bead. In practice, there are difficulties for evaluation residual stresses level in this situation. Some numerical methods modeled those stresses to validate the experiments. In this way, the main contribution of this work was the visualization and quantification of the stresses levels in welding of plane plates, using bidimentional photoelasticity.