3. Finite element analysis
The 3D mesh model of T-joint was established to
simulate the DP-MIG process using the commercial
software ABAQUS. As shown in Fig. 4, the model is
mostly made up of eight-node brick elements and
contains a total of 40200 nodes associated with 28000
elements. A very fine mesh size with an average value of
1 mm is used around the fusion zone. The mesh size
gradually increases with increasing the distance from the
fusion boundary to guarantee the simulation accuracy
and efficiency at the same time. The material suffers
from a thermal cycle during the welding process, so the
temperature-dependent physical and mechanical
properties of the 6061-T6 Al alloy are assigned to the 3D
simulation model