Development of numerical simulation model for FSW employing particle method

Abstract

The friction stir welding (FSW) has been used widely in the field of industry. Numerical analysis models for FSW also have been developed and there are many papers about it. In these papers, the most frequently used method is finite element method or finite difference method. However, by employing these methods, it is difficult or troublesome to calculate the advective term both for momentum and temperature. It is also difficult to calculate the big deformation of the material. Moreover, complex process is required to analyse the dissimilar joining with respect to dealing with substance transfer. In this paper, to avoid these difficulties or troublesome processes, particle method is adopted for dissimilar FSW simulation. In particle method, advective term, substance transfer and surface deformation are calculated automatically mainly because that Lagrangian approach is used. Performing some of analysis for FSW, the effectivity of this method is verified.

Clarification of material flow and defect formation during friction stir welding

“…Figure 4a shows a three-dimensional graph at 1000 rev min 21 . The tungsten tracer repeatedly rotates around the probe in a concentric circle.…”

“…a 1000 rev min21 ; b 800 rev min 21 ; c 600 rev min 21 ; d 400 rev min 21 ; e 300 rev min21 4 Three-dimensional graphs of tracer coordinates at tool rotation speed a downward view; b upward view 3 X-ray transmission images obtained by X-ray transmission real time imaging systems supplied into the stir region and the smooth material flow is realised.…”

“…-dimensional graph of tracer coordinates on TD-WD plane at 400 rev min 21 9 Cross-sectional images of stir zone formed at tool rotation speed of 400 rev min 21 the AS at 400 rev min21 . The size of the defect increased with a decrease in the tool rotating rate.…”

Friction Stir Welding of Medium Carbon Steel with Laser-Preheating

“…Regarding this material flow behavior during the conventional FSW, sufficient material flow region is formed on both the advancing side and the retreating side during the FSW of aluminum alloy whose heat conductivity is higher than that of carbon steel. 23) This is because the frictional heat and the deformation heat generated on the advancing side is sufficiently transported to the retreating side by the material flow during the FSW of aluminum alloy. On the other hand, the heat generated on the advancing side is insufficiently transported during the FSW of carbon steel whose heat conductivity is lower, so that the material flow region on the retreating side is smaller than that on the advancing side as shown in Fig.…”

Research of the friction stir welding process of aluminium alloys

“…Development of numerical simulation model for FSW employing particle method is presented in [14]. A smoothed particle hydrodynamics (SPH) model for FSW is proposed in paper [15].…”