RU1826023C - Specimen for bending, twisting and compression strength tests - Google Patents

Abstract

The invention relates to devices for testing materials and can be used to determine their strength under the combined action of bending, torsion and compression forces. The purpose of the invention is to increase the stability of the sample and to enable the change of direction of bending of the working area. The sample includes transition elements connected at one end with its working part, and the other with the same two-arm levers. The sample is also equipped with two additional levers, each of which is mounted on the centrally symmetrical shoulders of the main levers with the possibility of movement along them, and a cable designed to connect to the test equipment. The working part of the sample is provided with support elements for rigid fastening to the test equipment. When the cable is pulled by a power driver on the paЈq4yto part of the sample, bending, torsion and compressive forces are transmitted, the ratio between which can be changed by changing the position of the additional levers and the points of attachment of the cable to them. 4 ill. . (L C

Description

The invention relates to methods for testing materials and can be used to determine their strength under the combined action of bending, torsion and compression forces.

The purpose of the invention is to increase the stability of the sample and to enable the change of direction of bending of the working area.

In FIG. 1 shows a general view of the sample and its loading pattern; in FIG. 2 is the same. view from above; in FIG. 3 is a diagram of loading a sample with a changed position of levers; in FIG. 4 - same, top view.

The sample includes transition elements 1, 2, connected at one end to the working part 3, and the other perpendicular to the axis

the working part 3 with the same two-arm levers 4 and 5. The sample is also equipped with additional levers 6, 7. each of which is mounted on the centrally symmetrical shoulders of the main levers 4, 5 with the possibility of movement along them, and a cable 12, designed to connect with test equipment. The working part 3 of the sample is provided with elements (supports) 8, 9 for rigid fastening to the test equipment. The connection of the working part 3 with the elements 8.9 can be made rigid (for example, by welding) or with a predetermined gap between the surface of the working part 3 and the holes in the elements 8, 9.

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with

The sample is tested as follows.

Elements 8, 9 are connected to a fixed grip of the test rig. The levers b, 7 are set to the required position, the ends of the cable 12 are attached to the levers 6, 7 at points determined on the basis of the required ratio of torsion, bending and compression forces transmitted to the working part 3, and the cable 12 is tensioned by moving the exciter 10 of the test setup with roller 11 in the direction away from the sample. The branches of the cable 12 can be located both symmetrically with respect to the force P (in this case, the same bending, torsion and compressive forces are transmitted to the zones of the working part 3 located on different sides of the central support section), and asymmetrically with respect to the line of action of the indicated force (in In this case, the forces transferred to different zones of the working part 3 will have different values, and the implementation of this case is possible only with a rigid connection of the working part 3 with elements 8.9). The test at a given ratio of bending, torsion and compression forces is carried out with the cable 12 and levers 6, 7 in an unchanged position until the working part 3 is destroyed in the working sections located at elements 8, 9, for example, from their outer edge, where the greatest bending moment acts . If necessary, change the ratio of the forces transmitted to the working part 3 in the process (testing, this can be achieved by changing the position of the points of attachment of the cable 12 to the levers 6.7 or the position of the levers 6.7 relative to the working part 3, Signs of bending and torque transmitted working part 3 can also be changed

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by changing the position of the levers 6, 7 and the points of attachment to them of the ends of the cable 12. This is illustrated in FIG. 3, 4, which shows the position of the levers 6, 7 and the cable 12, with

wherein the signs of bending and torques transmitted to the working part 3 are opposite to those which are realized at the position of said elements, not given in FIG. 12.

The use of elements 8 and 9 increases the stability of the sample during loading, and the presence of additional two-arm levers 6 and 7, attached to the levers 4 and 5 with the possibility of movement along the latter, provides a change in the direction of bending of the working area.

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Claims (1)

SUMMARY OF THE INVENTION Bending, torsion, and compressive strength test specimen containing a working part, ideally centrally symmetrical heads made in the form of identical two-arm levers perpendicular to the axis of the specimen, and cables connected to the test equipment, characterized in that, in order to increase stability of the sample and the possibility of changing the direction of bending of the working area, it is equipped with two additional two-arm levers, each of which is mounted on the centrally symmetrical shoulders of the main p the levers can be moved along them, the cables connected to the measuring equipment are fixed on additional levers, the main and additional levers are fixed in a plane parallel to the axis of the sample, and the working part of the sample is equipped with an element for rigid fastening to the test equipment. L fig.Z Cabbage soup Mr. I d 3 / P