S102025 Study on the Effects of a Coefficient Restitution and Gyrosystem on Rocking Motion Reduction of a Cylindrical Structure.

Abstract

The spent fuels from nuclear power stations are stored in a cask until reprocessed. It is concerned that the cask turns over when an earthquake occurs, because it is generally freely standing on a horizontal floor. This study investigates the rocking motion of a cask experimentally and analitically using CAE software named MATLAB which can simulate the rocking motion. When earthquake occurs, rocking and sliding motion will occur at the same time, however we consider the motions separately. A cask is huge and the weight is about 157t, therefore we make a reduced scale model. The scale factor is 1/1000 and the weight is about 15kg In the experiment, we excite the experimental model by applying initial angle or sinusoidal wave, and rocking angle is measured. The experimental results are compared with the Analytical ones to check the validity of the analytical method. In the analysis, we vary the coefficient restitution, and study the validity of the analytical model on restitution coefficient Next, we suggest Gyro system in order to prevent the rocking motion This Gyro system gives the cask Gyroscopic effect, thus the rocking motion can be reduced In the analysis, it is found that the rocking motion can be suppressed.