SU1303888A1 - Installation for fatigue testing of material specimens - Google Patents

Abstract

The invention relates to the field of testing equipment. The purpose of the invention is to expand the technological capabilities of the installation by testing a group of samples 5, 13, 14 during their forceful interaction. To do this, the installation has an exciter 2 axial load and three energizers S (L 00 CO 00 oo 00

Description

6, 15 and 16 transverse bending. The force-pathogen 2 is placed on the frame and is made in the form of a crank 31 with a drive 32 of its rotation. Crank 31 is equipped with axial grippers 3, 9, 11 for samples 5, 13 and 14. Each force actuator 6, 15, 16 is designed as a radially curved guide in which a pusher is installed and a two-armed lever with a rotary axis. A guide is attached to one shoulder of the lever. The second arm of the lever is pivotally attached to one of a pair of axial grippers 4, 10, for attaching the axial joints of axial grip 4, 10, 12 or lateral 8, 17, 18

one

The invention relates to testing equipment, in particular, installations for testing samples of various materials, mainly rocks and materials used in the manufacture of mountain supports, for fatigue under the action of axial and bending loads.

The purpose of the invention is to expand the technological capabilities of the installation by testing a group of samples during their forceful interaction, ensuring adjustment of the ratio between axial and bending loads and ensuring regulation of the levels of loads on the samples in the group.

FIG. Figure 1 shows the setup for fatigue testing of material samples, front view; in fig. 2 - the same, side view.

The installation includes a frame 1, axial load energizer 2 placed in it, a pair of axial grippers 3 and 4 for sample 5, a transverse bending force silo 6 with a pusher 7 and a side gripper 8 for sample 5, additional pairs of axial grippers 9, 10 and 11, 12 for additional samples 13 and 14, installed in parallel with sample 5, additional force-actuators 15 and 16 of transverse bending with pushers (not shown) and side grippers 17, 18 for additional samples 13 and 14, and connecting rods 19 and 20

03888

rods 19 and 20 are present. When both rods are installed, they simultaneously receive a force exchange for axial and bending loads. To ensure the adjustment of the ratio between axial and bending loads, the levers of exciters 6, 15, 16 are made in the form of rails, their pivot axes are in the form of gears, and the crank 31 has variable eccentricity. In order to control the levels of loads on samples 5, 13, 14, the guide has a spring in contact with the pusher and a moving screw connected to the second end of the spring through a ball transmission. 2z.p.f-ly, 2 ill.

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for selectively joining axial grippers 4, 10 and 12 or side grippers 8, 17 and 18.

Each of the energizers 6, 15

. and 16 transverse bending is made in the form of a radially curved guide 21, in which a pusher 7 is installed, a two-arm lever made in the form of a swivel bar 22. an axis made in the form of a gear wheel 23, a spring 24 installed in a guide 21 and in contact with one end with a pusher 7, and a gland screw 25 connected to the second end of the spring 24 through a ball gear 26, while on one arm of the rail 22 the guide 21, the second shoulder of the rail 22, through the axis 27, is attached to one of a pair of axial grippers 4 and 10 or 12, and the gear wheel 23 is rotatably mounted by means of a wheel 28 with a loosened locking

, nut 29. To hold the rail 22 in engagement with the toothed wheel 23, there is a yoke 0.

five

0

JO

The axial exciter 2 is made in the form of a crank 31, on which axial grippers 3, 9 and 11 are second from each pair, and a crank 31 rotation actuator 32. Crank 31 is configured to change its eccentricity at 35 loosened locking screws 33.

The installation works as follows.

For group test mode operation without force interaction between samples 5, 13, and 14, rods 19, 20 are removed from axial grippers 4, 10, 12 and side grippers 8, 17, 18. The actuator 32 is turned on and during rotation of the crank 31 the axial grippers 3, 9, 11 make circular movements together with crank 31, axial grippers 4, 10 and 12 affect the left (Fig. 1) arms of the levers-rails 22, rotate them around the axes — the gears 23. When the rails turn, 22 rotates 21 energizers 6, 15 and 16 of transverse bending, the pushers 7 move relate flax guides 21 and compress the power springs 24. When the power springs 24 deform, the pushers 7 transfer to the patterns 5, 13 and 14 through the side ones. The jaws 8, 17 and 18 bending loads and simultaneously axial loads proportional to them, which appear as a result of the right arms of the lever rails 22. The ratios between the axial and lateral bending forces depend on the ratio of the arms of the lever-rails 22 and are adjusted by turning the gears 23 and moving the rails 22 while rotating the wheel 28 with the locking nut 29 relaxed. Limits changed and the loads are set by the eccentricity of the crank 31, which is controlled by the movement of the crank 31 with loosened screws 33: as the eccentricity increases, the limits of the loads change. The level of change of loads on each sample is regulated separately by pressing the power springs 24 by rotating screws 25 and moving the ball gear 26: as the degree of spring pressure increases, the lower and upper levels of loads increase. During testing, each of samples 5, 13 and 14 is destroyed individually without affecting the operation and loading parameters of adjacent samples.

For operation in the group test mode with force interaction for a change in axial load, axial grippers .4, 10, 12 are connected to each other by a rod 19. Otherwise, the course of the tests is the same as in the described

n mode. With the relaxation of axial stresses on one of the samples 5, 13 and 14, its lower axial gripper 4, 10 or 12 continues to move along with the other lower axial grippers of the other samples, and the specimen leaves the axial load. Moreover, since the lower grip of the weaker sample moves within the previous limits, and its breakdown is at the level of the deflection of the remaining samples, the force on its lower grip, created by the deformation of its force spring 24, does not decrease and through the rod 19 goes to other samples. On the weak sample under consideration, axial tension occurs, but not at a constant length, but when its length changes, together with the rest of the samples. The force is transferred from one sample to another.

0

25

This is the axial load power exchange.

35

40

For operation in the group test mode, when the force interacts, the bending load changes, the rod 19 is removed and the

JQ rod 20, the grippers 8, 17, and 18 are connected to each other. In an attempt to accelerate the development of a deflection on one of the samples 5, 13, or 14, its lateral grip 8, 17 or 18 does not move relative to the other lateral grippers, all the lateral clamps 8, 17 and 18 provide the same deflection of all samples 5, 13 and 14. Since the axial deformations in this case are slightly different from each other, all the lever rails 22 continue to make turns within almost equal angles with the former deformation of the force springs 24. Total bending force on all sam ples 5, 13 and 14 is not reduced, so the care from the bending load of one of these samples at its relaxation bending stresses

0, the bending load is transferred to adjacent samples. There is an increase in bending forces on other samples in the group, which is a force exchange in the group on the bending load. The adjustment of test parameters is carried out in the same way as in the described modes.

When installing both rods 19, 20 at the same time receive a power exchange as axial loads.

the same bending formula

Claims (3)

1. An installation for testing fatigue of material samples, comprising a frame, an axial load force exciter, a pair of axial grips for the sample, and a transverse bending force activator with a pusher and a side gripper for the sample, associated with an axial stress energizer, characterized by the fact that, in order to expand the technological capabilities of the installation by testing a group of samples during their forceful interaction, it is equipped with additional pairs of axial grippers — according to the number of additional samples — it will add with transverse bending exciters with pushers and side grippers for additional samples and connecting rods for selectively connecting axial or lateral grips, each transverse bending force actuator made in the form of a radially curved guide j in which the pusher and two arms are installed swivel arm   - well five 0 five 0 an axis on which a guide is fixed on one shoulder, the other shoulder is pivotally attached to one of a pair of axial grippers, and the axial load remover is made in the form of a crank, on which the second of each axial gripper is mounted, and the crank rotation drive. 2. The installation according to claim 1, characterized in that, in order to ensure the regulation of the ratio between axial and bending loads, the two arms of the transverse bend forces are made in the form of rails, their turning the axes are in the form of gear wheels mounted for rotation, and the crank of the axial load force actuator is adapted to change its eccentricity. 3. The installation according to claim 1, characterized in that, in order to control the levels of loads on the samples in the group, it is equipped with a power spring installed in a radially curved guide and contacting one end with the pusher and a gland screw associated with the other end of the spring through the ball transmission. A.Dolinich figure 1 Compiled by V.Talvoysh Tehred I.Popovich. 1299/42 Circulation 777 Subscription VNIIPY USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 Proofreader S. Shekmar