Adding hardening to the material model

The connecting lug simulation with perfectly plastic material behavior predicts that the lug will suffer catastrophic failure caused by the collapse of the structure. We have already mentioned that the steel would probably exhibit some hardening after it has yielded. You suspect that including hardening behavior would allow the lug to withstand this 60 kN load because of the additional stiffness it would provide. Therefore, you decide to add some hardening to the steel's material property definition. Assume that the yield stress increases to 580 MPa at a plastic strain of 0.35, which represents typical hardening for this class of steel. The stress-strain curve for the modified material model is shown in Figure 1.

Figure 1. Modified stress-strain behavior of the steel.

Modify your plastic material data so that it includes the hardening data. Edit the material definition to add a second row of data to the plastic data form. Enter a yield stress of 580.E6 with a corresponding plastic strain of 0.35.