2.2.2. Validation of Mesh Insensitivity

The traction structural stress method has mesh insensitivity. In the finite element simulation process, only the geometric features of the weld toe of the T-joints need to be fully considered, and a rougher mesh can be used to obtain a relatively accurate result.

In order to verify the mesh insensitivity of the structural stress method, three FE models with mesh sizes of 4 mm, 2 mm, and 1 mm were used to calculate the structural stress of T-joints.

The finite element modeling, meshing, constraints, and boundary conditions of the T-joints are shown in Figure 5. The 70 mm long area at the left and right ends of the models is limited Y-direction displacement, and the rotation and movement of the left end of the models in X and Z directions are constrained, ensuring that the boundary conditions in the finite element simulation process are consistent with the actual fatigue test. A load of 1 MPa was applied to the right end of the test specimens. As shown in Figure 6, the trend of the traction structure stress curve at the same stress extraction position under three different mesh sizes was basically the same, and the maximum stress of the traction structure was 1.0831 MPa, which verifies the mesh insensitivity of the traction structure stress method.

Finite element modeling, meshing, and boundary conditions.

The traction structural stress of T-joints with different mesh sizes.