Lap Shear Simulations The standard lap specimen geometry was simulated with different FEM resolutions. Geometry of very detailed FEM discretization is shown in Figure 36. The clamped regions are cut off in the model and replaced by the clamped boundary conditions on the nodes emerging from the clamps. As such, the model does account for any grip slipping and is expected to exhibit stiffer response than experiments. Figure 37 shows the simulation side view of the spot weld region of the lap shear test with small nugget diameter, and coarse FEM mesh. The figure shows configurations before and after the failure. The failure of the spot weld in simulation and experiments was along the interface between the two connected sheets. Comparison of the force-displacement data from simulation and the quasi-static test is shown in Figure 38. The failure of the spot weld in simulation and experiments was along the interface between the two connected sheets. Figure Lap shear specimen model. Detailed FEM mesh Figure 37 Lap shear test simulation for small spot weld nugget diameter (4.3 mm). DP780 steel. Figure Comparison of the resulting force for experiments and simulations for DP780 steel, small spot weld diameter (4.3 mm). The resulting force comparison is very close given the experimental scatter and the simplicity of the failure model. Simulation for large spot weld diameter in lap shear test is shown in Figure 39. The resulting force comparison in Figure 40.is again reasonably close to the resulting force and stiffness of the assembly. The spot weld model accurately recovers geometry effect [99] based on intrinsic material properties and a very simple failure condition, without a need for accounting of any extrinsic joint properties such as nugget diameter. Simulations with a rigid nugget core (Model 1R) yielded essentially the same results. Figure 39 Lap shear test simulation for large spot weld diameter.
Lap Shear Simulations The standard lap specimen geometry was simulated with different FEM resolutions. Geometry of very detailed FEM discretization is shown in Figure 36. The clamped regions are cut off in the model and replaced by the clamped boundary conditions on the nodes emerging from the clamps. As such, the model does account for any grip slipping and is expected to exhibit stiffer response than experiments. Figure 37 shows the simulation side view of the spot weld region of the lap shear test with small nugget diameter, and coarse FEM mesh. The figure shows configurations before and after the failure. The failure of the spot weld in simulation and experiments was along the interface between the two connected sheets. Comparison of the force-displacement data from simulation and the quasi-static test is shown in Figure 38. The failure of the spot weld in simulation and experiments was along the interface between the two connected sheets. Figure Lap shear specimen model. Detailed FEM mesh Figure 37 Lap shear test simulation for small spot weld nugget diameter (4.3 mm). DP780 steel. Figure Comparison of the resulting force for experiments and simulations for DP780 steel, small spot weld diameter (4.3 mm). The resulting force comparison is very close given the experimental scatter and the simplicity of the failure model. Simulation for large spot weld diameter in lap shear test is shown in Figure 39. The resulting force comparison in Figure 40.is again reasonably close to the resulting force and stiffness of the assembly. The spot weld model accurately recovers geometry effect [99] based on intrinsic material properties and a very simple failure condition, without a need for accounting of any extrinsic joint properties such as nugget diameter. Simulations with a rigid nugget core (Model 1R) yielded essentially the same results. Figure 39 Lap shear test simulation for large spot weld diameter.
SPW_Report_v6.docx