Numerical and experimental investigation of T-shape fillet welding of AISI 304 stainless steel plates

Current study uses experimental data to develop an empirical relationship to model welding process in a fillet-weld joint of AISI 304 stainless steel plates. A new Double-Ellipsoidal Heat Source (DEHS) model, which is based on Goldak model, is developed to simulate fillet-welding process. Then, the extended model is implemented into a finite element code on which a 2D and also a 3D solutions are used to simulate the temperature field in the weldment. A series of experimental measurements and numerical analyses have been carried out and the effects of temperature dependent material properties and welding heat input on temperature field and deformation are investigated. The results are compared with the experimental data, and the constants of the empirical relationship have been obtained using model updating method. For this purpose, an optimization computer code has been developed to modify the initial values in order to update the model to achieve agreement with measured data. The results show that 2D model can only be used in thermal analysis; whereas, the developed 3D model can predict thermo-mechanical behavior with acceptable accuracy. The major advantage of this formulation is that the number of unknown coefficients has been reduced to only one coefficient and other coefficients have been related to the physical or geometrical parameters that are known for each weldment.