Development of a Three-Dimensional Heat-Transfer Model for the Gas Tungsten Arc Welding Process Using the Finite Element
- PDF / 613,122 Bytes
- 13 Pages / 593.972 x 792 pts Page_size
- 39 Downloads / 212 Views
he fusion-welding process, the computational models are established as significant routes for a priori estimation of peak temperature, weld-pool dimensions, cooling rate, and several other features of the weld pool and the surrounding heat-affected zone.[1,2] Following Rosenthal’s pioneering modeling efforts, researchers[3–7] developed analytical models for the estimation of temperature field in fusion arc welding. The usability of these analytical solutions were restricted due to the consideration of welding arc as a point heat source, assumption of constant material properties, and neglect of latent heat of melting and solidification. One of the initial attempts to numerically model the heat-transfer process in fusion welding was by Mazumder et al.[8] A laser-welding process was numerically modeled considering the laser beam as a distributed heat source with a Gaussian distribution. The material properties were considered to be independent of temperature. Chande et al.[9] had used an enhanced value of thermal conductivity in the weld pool to account for the strong circulating flows in the molten-weld pool and the resulting convective transport of heat. Goldak et al.[10,11] introduced a double ellipsoidal volumetric heat-source model S. BAG, Research Student, and A. DE, Associate Professor, are with the Mechanical Engineering Department, IIT Bombay, Powai, Mumbai 400076, India. Contact email: [email protected] Manuscript submitted October 31, 2007. Article published online July 26, 2008 2698—VOLUME 39A, NOVEMBER 2008
to account for the heat transport inside the weld pool using conduction-based heat-transfer analysis. Wahab et al.[12] also used a double ellipsoidal volumetric heat source to develop a quasi-steady heat-transfer model for gas metal arc welding process. The expression for the double ellipsoidal volumetric heat source contained six empirical constants that were calibrated by comparing the computed weld dimensions with the corresponding measured results.[12] Similar modeling efforts were reported by Bonifaz,[13] Reddy et al.,[14] and Dutta et al.[15] for gas tungsten arc welding (GTAW) process. The heat conduction–based models[8–18] are, of course, silent to questions on how the molten metal flows within weld pool and influences the final weld shape. Significant efforts are also made to develop convective heat transport–based model to analyze both heat transfer and fluid flow in the molten-weld pool by solving conservation equations of continuity, momentum, and energy equations under constant pressure field.[19–37] Oreper et al.[19] indicated that the influence of both the Lorenz force (electromagnetic force) and Marangoni force (due to surface tension) could be significant in the overall convective heat transport in the weld pool. Mundra et al.[20] reported that the surfacetension coefficient and viscosity would play a significant role in weld-pool development. Babu et al.[21] developed a two-dimensional (2-D) analytical model of fluid flow considering a laminar flow in the weld pool. Choo et al.[22] analyzed both laminar and t
Data Loading...
