PERFORMANCE OF DIGITAL ACCELEROGRAPH BY SHAKE TABLE TESTING

Abstract

In this work a comparative study between Analog and Digital accelerographs have been done. For this purpose two analog type viz. RESA-V and SMA-1 and a Digital accelerograph '(developed recently by Department of Earthquake Engineering, University of Roorkee, Roorkee) were fixed on.the Shake Table. A motion was given to the Shake Table and it was recorded on all three accelerographs. The motion fed to the table was of Koyna earthquake. Then from the recorded data which gives us acceleration time history, the velocity and displacement time histories were computed and being plotted. Also response spectra c% for acceleration, velocity and displacement timehistories were computed, plotted and compared. The fourier spectra: were also calculated for acceleration, velocity and displacement time histories and plotted also mean, median and variance for these spectras were computed and compared. Also areas under various bands under fourier spectra have been computed and compared. All the computations have been done using various computer softwares. The comparative study indicates that the records obtained from Analog accelerographs should be used carefully if they are to be used for getting velocity and d&splacement time histories from acceleration time history- Also results of comparative study indicates that Digital accelerograph gives better data.