Abstract
Presently, mechanical structures in nuclear power plant are usually designed statically and elastically. However, it is very important to grasp dynamic seismic safety reliability especially in unexpected severe earthquakes. Therefore new evaluation method that considers dynamic strength is required. In this study, dynamic ultimate strength is investigated from the viewpoint of energy balance. Energy balance is a method valid to evaluation of cumulative damage. Vibration experiment that induced experimental model to fatigue failure is examined, and the experimental result is arranged by energy balance method. Consequently a relation between fatigue failure and input energy to experimental model is confirmed.
