Seismic test and analysis of HTGR core using one-stacked block column

The results of a seismic test and analysis on a 1/2 scale model of the typical stacked column, an element structure for the seismic study of the block-type fuel core of a high temperature gas cooled reactor, are described. (1) The column has the soft spring characteristics based on the block rocking. The hard spring characteristic is observed based on the gaps between column and boundary. The column has a non-linear resonance and exhibits a hysterisis response with jump points. (2) The column resonance frequency decreases with increasing excitation amplitude. (3) The impact force increases with increasing input acceleration. (4) The impact force increases with increasing boundary gap width. (5) The maximum response of the column for seismic waves are about 40 to 75% of that for the sinusoidal input. (6) The column damping factor is about 30% of critical. It increases with increasing in the column deflection amplitude. (7) Good correlation in vibration behavior of the stacked column and impact force between test and analysis was obtained. (author)