TWI

A fully Lagrangian smoothed particle hydrodynamics method was employed to simulate the bobbin tool friction stir welding process for aluminium alloys in order to evaluate tool torque and forces as well as material flow for different advancing speeds. Welding experiments were performed on AA 6061-T6 alloy plates (thickness 6 mm) with a bobbin tool positioned in the mid plane of the workpiece. Process simulation was conducted using a coupled thermomechanical algorithm in the commercial code LS-DYNA v971 R7.00. Simulations were carried out for a rotational speed of 600 rpm and welding speeds of 800-1200 mm/min. A Johnson-Cook material model was invoked to incorporate the thermal softening of the aluminium alloy at higher temperatures. The prediction of defects such as blowout holes at the entrance and exit region is discussed.

10th International Symposium, 20-22 May 2014, Session 4B: Modelling I, Paper 02