Study on the Crash Simulation Model for the Protective Member of Flexible Structure

Abstract

The protective member of flexible structure such as the protective net has been developed against tornado missiles in nuclear power plants. However, modeling methods/knowledge of flexible structure were not much reported as compared with stiff structure like concrete walls. In order to obtain the modeling methods, a comparative study has been carried out about simulation models where a sheet of protective rope net subjected to impact loading with a free drop weight is modeled using various materials/conditions. Here, ropes of the net are modeled with beam elements, while a steel flame supporting the net is modeled with shell elements. The simulation results show that it is better not to consider compressive stiffness about the material model of the ropes. As for the frame using an elasto-plastic material, it is important to consider strain rate dependency of flow stress. It is also found that the turnbuckle which connects the ropes and outside of the frame should be modeled with rigid body and that boundary conditions considered here for the frame do not influence the result so much.