THE PREDICTION OF THE TEMPERATURE DISTRIBUTION AND WELD POOL GEOMETRYIN THE GAS METAL ARC-WELDING PROCESS

The main objective of this study is to generate new understanding and improve computer methods for calculating the thermal cycles in the nea r weld region during gas metal are (GMA) welding. Predicting the therm al cycle also provides an estimate of the depth of weld penetration, t he geometry of the weld pool and the cooling rates. Both 2D and 30 fin ite-element models have been developed using the solution of heat-tran sfer equations. The accuracy of the predicted cooling times, weld pene trations and the lengths of the weld pools are compared with experimen tally obtained values for bead-on-plate welds. A mechanical weld pool ejection rig developed in this study provided a quick and ready means of defining a full 3D weld-pool shape. A new numerical approach, 'spli t heat source model' has been developed to model the are heat. This gi ves good agreement with experimental data for a range of welding condi tions. (C) 1998 Elsevier Science S.A. All rights reserved.