Weld process model for simulating metal active gas welding

Abstract

Generally, optimum welding variables and conditions of manufacturing are currently mainly determined by experiments for standardized production. Virtual manufacturing and virtual testing of weldments using finite element method provide a sustainable solution for advanced applications. The aim of the current research work is to develop a weld process model, using a three-dimensional heat transfer model, to ensure general applicability for typical joints of stator segments of wind turbines as a final application. A systematic experimental research program, containing temperature measurements during welding, macrographs, and deformation measurements, is carried out on small-scale test specimens using different welding variables. In addition, a numerical study using uncoupled transient thermomechanical analysis is performed. The weld process model uses Goldak’s double ellipsoidal heat source model for a metal active gas welding power source. It describes the correspondence between heat source parameters and net heat input for two types of electrodes. The model is validated via cross-sectional areas of fusion zones and deformations based on experiments. The relationship between current and voltage is determined based on large number of experimental data; thus, selecting a wire type, travel speed, and voltage directly defines the heat source parameters of the weld process model.