SU1285341A1 - Bed for testing structures - Google Patents

Abstract

The invention relates to These tests of building structures for strength and rigidity and allows to ensure the possibility of Dani’s complex loading and expansion of the range of tested structures (IR). The stand contains twin mounts 3, support 1 and distribution 2 beams (B) with central holes 4 and 5 through which axles 7 pass. On axis x 7 or on walls of holes 4 and 5, they are fixed at right angles to each other. to a friend hydraulic cylinders (HZ) 8-15. They rotate around the axes in 360 ° C with the help of winches fixed on the throat 3. T gi 3 are pivotally interconnected by means of axles / 57 (L yu cf SP 4

Description

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7 and bolts 6 with the corresponding B 1 and 2 with the formation of two trihedral prisms with opposite vertices. The HZ 8-15 rods interact with the surface of the holes 4 and 5 and with the axes 7 and are rigidly connected to each other. With increasing pressure in HZ 8-15, increasing loads are transmitted through the corresponding B 1 and 2 to IC 17. When the loading point is reached, corresponding to the last stage of the load

in IR 17, in the middle of the height, stretch and shear are created at zero bending moment. To carry out more complex loading, pressure in HZ 8-15 is changed. First, IC 17 is transferred from tension to compression, then the compressive force is fixed and the direction of the shear force is reversed. The shear force is fixed and the compression is changed to stretch in IR 7, 1 hp, f-crystals, 5 sludge.

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The invention relates to the field of strength and rigidity testing of building structures, namely, stands for testing building structures,

The purpose of the invention is to provide the possibility of creating a complex loading and expansion of the range of tested structures,

Fig. 1 shows a stand for testing building constructions, side view; Fig. 2 shows load structures of the structures in the stand; Fig. 4 shows the forces applied to the structure at the first load path; Fig. 4 shows the forces applied to the structure, etc., to the second load path; Fig. 5 shows a stand, an embodiment.

The stand contains support beam 1, distributor beam 2 and bars 3, Beams and 2 have centrally located through holes 4 and 5, respectively. The twin rods 3 are articulated to the corresponding beams 1 and 2 with fastening bolts 6 and are articulated, interconnected by means of the axles 7, passing through the centers of the holes 4 and 5, while the dual rods 3 with the corresponding beams 1 and 2 form triple prisms with oppositely directed vertices.

On axles x 7, hydraulic cylinders 8–11 and 12–15 are hinged at a right angle to each other with the possibility of turning them around axes 6 through 360, for example, using winches (not shown) fixed to.

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In this case, the rods of the hydraulic cylinders 8-11 interact with the surfaces of the aperture 4, and the rods of the hydraulic cylinders 12-15 interact with the surfaces of the aperture 5, to provide the possibility of testing structures of various dimensions on beams 1 and 2 and 3.

The tests are carried out as follows.

A test program is preliminarily developed and a test stand is prepared for testing, for which the twin rods 3 are attached to the beams I and 2, passing the clamping bolts 6 through the corresponding hole 16,

After that, the hydraulic beam 13 lifts the distributor beam 2 with the straps 3 attached to it. Then, the test structure 17 is put on the side with a rake 3, installed and fixed on the support beam 1, Next, the hydraulic beam 13 lowers the distribution beam 2 to the structure 17 and fixes it are on it.

Test design for simple loading.

Fig. 2 shows a diagram of a test of a structure with axes of coordinates: the axial force P is the shear force T, Point M corresponds to the last stage of loading, beam A corresponds to simple loading. Hydraulic cylinders 8-11 and 12-15 are set to a predetermined position by turning them at a certain angle.

As the pressure increases in the cylinders 8-11 and 12-15 are transmitted

increasing loads O through the corresponding beams 1 and 2 on the structure 1 7.

When the point M is reached in the structure, a stretch P and a shift T are created at a zero bending moment in the middle of the structure height. These forces and the loading path cause a certain deformed state.

Test design for complex loading.

From the diagram (Fig. 2) with the axes of the coordinates: axial force - shear force, it follows that point M corresponds to the last stage of loading, and beam B corresponds to complex loading.

. At the first stage, in the construction in the middle of the height, a pure shear is created, which is achieved by creating pressure in the cylinders 8 and 12 (position shown in Fig. 1), which transfers the increasing load T through the corresponding beams} and 2 to the design 17. When reaching the values include the hydraulic cylinders 9 and 13, which create tensile forces P with constant shear force T ". When the point M is reached in the structure, the same stress state is created as in the first load path, but a new one deforms: my state, depending on the plastic properties of the material.

With the help of the immersible system of hydraulic cylinders, it is possible to conduct a design test along a more complicated path (Fig. 2, B). For example, at the first stage, by simple loading, come to the point Mj, and then, having changed the pressure in hydraulic cylinders 8-15, first go from tension to compression, then fixing the compressive force, change the direction of the shearing force to the opposite, fixing the shearing force, change the compression in tension in construction 17, and, by changing the shearing force, return to point M.

Hydraulic cylinders 8-15 can be installed on the walls of the holes

4 and 5 in such a way that their rods interact with axes 6 passing through the centers of holes 4 and 5 in beams 1 and 2. Such installation of hydraulic cylinders provides a test

both flat structures 17 (Fig. 5, dashed line) and rod structures 18 due to the transformation of the stand design scheme from the kinematic system to the statically determined

my system.

Claims (2)

1. Stand for testing building structures containing opera and distribution beams, made with centrally arranged through holes, twin rods pivotally interconnected by means of axes passing through the centers of the holes in the beam, and with corresponding beams with the formation of two trihedral prisms with oppositely directed verptines and two hydraulic cylinders pivotally mounted on the axles, distinguishing - so that, in order to ensure the possibility of creating complex loads of the tested structure, it is equipped with six additional hydraulic cylinders pivotally mounted po.tri on each axle, while the cylinders are mounted on the axes with the possibility of their interaction rods with the surface of the holes of the beams and are rigidly connected to each other with the formation of right angle. 2. A stand according to claim 1, characterized in that, in order to enable the range of tested structures to be expanded, the hydraulic cylinders are fixed on the walls of the openings of the beams with the possibility of their rods interacting with the axles. A.g f Tn ./ 3 AftV Schr /// /// /// 77 FIG. five