Experimental Estimation of Dynamic Plastic Bending Moment for Plastic Hinge Model.

In the present paper, the experimental estimation of dynamic plastic bending moments for metal strips is investigated. The three-point bending test under impact and static loads is applied to aluminum alloy (JIS A 6063 S) and mild steel (JIS SS 400). It is confirmed that the dynamic bending deformations in the three-point bending test can be modeled as a plastic hinge, the experimental results show that the absorbed energies of the specimens are proportional to the bend angles. The ratio of the absorbed energy to the bend angle is approximately equal to the plastic bending moment. In the case of aluminum alloy, the dynamic bending moments for the different average bend angular rates coincide with the static bending moments. On the other hand, in the case of mild steel, the dynamic bending moments are proportional to the average bend angular rates. These results show the strain rate effect for mild steel and aluminum alloy which are known well. As a result, we confirm that the present method based on the plastic hinge model and the absorbed energy is efficient for determining the dynamic plastic bending moment.