Full-scale dynamic testing of raised floor structures

Abstract

At the moment there is a rather small piece of the information about the behavior of the raised floor under the seismic impacts, and at the same time the spectrum of such structure application is continuously expanding, that leads to the necessity of the detailed assessment of their characteristics. The research purpose is to determine the resonant frequencies and transfer functions of the raised floor elements and the whole structure at all. The determination of the raised floor structure vibrostability in the frequency range 1 - 30 Hz is determined in the case of the sinusoidal oscillations influence of the basement, too. During the preparatory work the testing platform was constructed, it simulates the full-scale boundary conditions for a raised floor panel installed on the concrete basement in the enclosed room with a tight fit to vertical walls along the contour. Thus, the deformations of the raised floor fragments were neglected because of the racks compliance and joints. Also, the stepwise loading scheme was developed to determine the limiting states and possible destruction of the raised floor elements. As a result of the studies, the oscillation accelerograms of the raised floor fragments were obtained at the given level of seismic impacts; the dependence of the stresses in the raised floor elements on the time at the given level of seismic impact and fixing the defects of the raised floor elements during and after the test series are determined.