Incompressible SPH Simulation of Weld Pool Convection with Molten Metal Droplets in a GMA Welding

Abstract

In this study, the convective flow in a weld pool during a GMA welding process was clarified by a numerical simulation using an incompressible smoothed particle hydrodynamics method. The computational domain of this simulation was a two-dimensional vertical section of a base metal along the welding direction in a system whose consumable electrode moved. The simulation revealed that the molten metal droplet fell into the weld pool and generated a wave which travelled backward. When the wave hit the solid bead, it swelled up as it solidified generating a wavy surface, which is observed in actual GMA welding. The flow inside the weld pool was also simulated. Both the height of the formed reinforcement and the depth of the penetration agreed with experimental results, which presented the validity of this simulation.

Particle simulation of nugget formation process during steel/aluminum alloy dissimilar resistance spot welding and thickness estimation of intermetallic compounds

“…ティグ溶接やミグ溶接の溶融池対流現象 [10][11][12][13] ，ミグ溶接やフ ラックスコアードアーク溶接の溶滴移行現象 14,15) ，サブマー ジアーク溶接現象 16) などの溶接・接合分野においても応用 されており [17][18][19][20][21]…”

Visualization of electromagnetic-thermal-fluid phenomena in arc welding

“…A salient advantage of the particle method is simple handling of moving boundaries accompanying free surfaces or phase change. Its application examples to studies of the arc welding process include the numerical simulation of internal thermalfluid phenomena during weld pool formation in GTA welding [39][40][41][42] and GMA welding, [43][44][45] conducted by the present author and colleagues using smoothed particle hydrodynamics (SPH), 46) a kind of particle method. Studies of other welding processes include two-dimensional simulation of a current within a weld pool in laser spot welding using the SPH method reported by Tong and Browne 47) and the simulation of friction stir welding using the moving particle semi-implicit (MPS) method 48) reported by Yoshikawa et al 49) The particle method discretizes a continuum as an ensemble of computational particles to express the evolution of the continuum collectively, by accelerating (or decelerating) and driving each computational particle according to the laws of motion.…”

High speed X-ray observation of digital controlled submerged arc welding phenomena

“…Hence, the details of SAW have not been elucidated yet because the coverage of flux prevents direct observation. To tackle this problem, numerical simulations were performed with a grid-based method [10,11] and a particle-based method [12,13] which combined a discrete element method and a smoothed particle hydrodynamics used for a gas metal arc welding simulation [14][15][16][17] with an incompressible approximation [18]. Those works showed the inherent phenomena of SAW and revealed the welding mechanism and energy balance.…”