CS200839B1 - Table for modelling of seismic effects - Google Patents

Description

It is an object of the present invention to model seismic effects for reeling structural elements and structural aystems, or models thereof, wherein the work surface is supported on resilient elements allowing linear motion and / or linear motion. horizontal linear vibration.

Both basic and applied research are often engaged in theoretical and experimental studies of the behavior of building components in areas with seismic activity. Experimental trials, which are indispensable in these studies, use several types of tables, respectively, to model these effects. ρίοδ, ίη. While these essentially satisfy the requirements imposed on them, some types of these devices do not provide perfect linear motion. E.g. platforms mounted on rocker stands, or platforms guided on liquid films in turn require high excitation forces at higher oscillation speeds, or floating platforms even limit the excitation speed at all. Tables mounted on rolling elements are generally noisy, and on models tested with a high center of gravity and higher excitation speeds, the inertia forces may change from the load-bearing force on the rolling elements and hence the impact, or the tables must be designed in considerable lengths.

The above-mentioned drawbacks are eliminated by the seismic effect modeling table according to the invention, which consists in that the frame is attached by means of four elastic elements to the fixing plate, each elastic element being formed from outer springs which are

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200 038 fixed in the center by the lower mounting bracket and the inner springs, which are fixed in the center by the upper mounting bracket. Internal and external springs are fixed at both ends by means of shims and intermediate shims. The size of the intermediate liners must correspond to the spacings on the fixing brackets, the inner and outer springs being parallel to each other, and there must be gaps in the horizontal direction between the upper and lower mounting attributes corresponding to the least elastic deformation of the inner and outer springs.

The dimensions of the springs are chosen so that the active length is one to two times the width, and their thickness is of the order of magnitude less than their width. The spring assembly so arranged allows a linear movement of up to two in a direction perpendicular to the spring plane, but for better stiffness in all other directions, four such beams are connected so that the mounting brackets of the larger springs are attached to the rigid frame and the mounting brackets board or grate. The fastening of the stirrups may also be reversed. In this way, not only the stirrups of the inner and outer springs can perform a linear movement with respect to each other, but also the plate, respectively. grate mounted on them, to the extent of elastic deformation of the springs; A suitable source of excitation force, which can be electric, mechanical or hydraulic, is connected to the grate. The device thus described can be built for loads ranging from a few kN to a few MN and a vibration amplitude size plus, minus a few cm.

In the attached drawing, FIG. 1 is a schematic diagram of a hydraulic seismic seismic stroke, and FIG. 2, a spring element made of four springs is shown in the axonometric drawing, wherein the outer springs 6 are rigidly connected in the center by the lower mounting bracket 8 and the inner springs 10 are rigidly connected by the upper mounting bracket χ. The inner springs ^and outer springs 6 are connected together at the ends by means of shims 9 and intermediate liners 10. The size of the intermediate liners 10 must correspond to the spacing on the mounting brackets 2 and 8, so that the inner springs and outer springs 6 must be parallel to each other. In this case, gaps χ must be formed between the lower fastening bracket 8 and the upper fastening bracket 2 with a size corresponding at least to the resilient deformation of the springs 6 and 6 in a direction perpendicular to the plane of the springs. The elastic element thus formed (FIG. 1), like the spring of the springs, forms the basic part of the seismic gallery. If at least four such resilient members 9, likewise oriented by the lower fastening bracket 8, are fastened to a sufficiently rigid frame 1 and fixed to the upper fastening bracket 2 firmly with a rectangular-shaped fastening plate 2 in its corners, It can be seen from the hydraulic cylinder 4 ύθ that the linear movement of the fixing plate 2 of the seismic table so formed can be caused by a mechanical or electric exciter, while the time course of the linear movement can be harmonious or even stochastic. It can be proved that by suitable choice of spring size and number of springs, which must always be an integer multiple of four, but also by number of elastic elements, seismic st61 can be designed practically for any load as well as for sufficiently large vibration amplitudes. The magnitude of the displacement will be proportional to the adjusting force. In harmonic oscillation the magnitude of the path amplitude, resp. The excitation force will also depend on the ratio of the natural and the excitation frequency.

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Described system of flexible mounting of fastening thatch, respectively. The grate can also be used for other types of tests where it is desirable to provide a perfect straight oscillating movement.

Claims (2)

OBJECT OF THE INVENTION 1. is compatible with the modeling of working surface-based seismic effects based on linear motion elements, characterized in that a fixing plate k2) is fastened to the frame (1) by means of four resilient elements (3), each resilient element k3) is formed from outer springs (6) which are connected in the middle by a lower mounting bracket (8) and from inner springs (5) which are connected in the middle by an upper mounting bracket (7), inner springs k5) and outer springs (6) are connected at both ends by means of shims (9) and cross-shims (10) the size of which corresponds to the spacing on the mounting brackets (7, 8), the inner springs (3) and outer springs (6) being parallel to each other and between the upper mounting bracket ( 7) and the lower mounting bracket (8) are gaps <y) of the size corresponding to the least elastic deformation of the springs (5 θ 6) · 2. StSl according to claim 1, characterized in that the inner springs (5) and the outer springs (6) are equally large, their effective length (c) being one to twice the width (h) and the thickness; less than the width (h) and the total number of springs (5 and 6) in one spring element (3) is an integer multiple of Number Four.