SU732731A1 - Arrangement for fatigue tests of flexible samples - Google Patents

Description

one

The invention relates to devices for investigating the strength properties of materials, namely, devices for fatigue testing of flexible specimens, for example ropes, under the simultaneous action of bending and tensile loads.

A device for testing flexible fatigue samples is known, comprising a base, spring-loaded grippers for flexible samples mounted on it, a mechanism for creating a cyclic load, made in the form of mobile supports associated with a reciprocating drive, and a pre-tensioning mechanism

1. The drawback of the device is

the absence of intermediate rollers around the sample and protecting it from destruction at the attachment points. The closest SIB device to the invention is a device for testing flexible fatigue specimens containing a base, a pre-tensioning mechanism, a spring-loaded grip associated with it, rollers around the specimen end sections, a mechanism for creating a cyclic load and a dynamometer, wherein the mechanism for creating a cyclic load is made by a crank rod, acting on the sample with the help of support segments, making a reciprocating motion 2.

The disadvantage of this device is that the use of a crank mechanism significantly limits the achievable load frequency, increases the time of testing a single sample.

The aim of the invention is to increase test performance.

This goal is achieved by the fact that the mechanism for creating a cyclic load is made in the form of a rotating disk, a bar hinged on an eccentricity disk with respect to

37327314

its axes, and two blocks with parallel

Claims (2)

axes placed on the plank, between the crown of a revolution, bend the patterns, a gap is formed for the test specimen. In addition, the plate has longitudinal slits for the installation movement of the axes of the blocks in them. FIG. 1 shows the proposed device; in fig. 2 - section A-A of FIG. 1. The device contains a rotating disk 1 mounted on the base 2. An 8-bearing disk support houses an axis 4 with which the bar 5 is rigidly connected with longitudinal slits 6 and 7, which is installed with an eccentricity relative to the axis of the disk 1. B-slot x 6 and 7 axes 8 and 9 of blocks Yu and 11 are fixed in parallel. Axes 8 and 9 are mounted in supports D2 and 13. The elements described above form a mechanism for creating a cyclic load. One of the sample 14 rolls around the roller 15 and is connected to the dynamometer 16, and the other rolls around the roller 17 and fastens in the gripper 18, in the case 19 of which the pre-tensioning mechanism containing the spring 2O, screw 21 and nut 22 is located. The device works as follows . When the disk 1 rotates, block 10 bends the flexible sample 14, increasing the angle of coverage of the block with the sample. At the same time, blocks 10 and 11 are pivoted on supports 12 and 13, and axis 4 and associated strap 5 rotate on bearing support 3. After the disc has completed one quarter of a turn (shown in Fig. 1 with a dash), the angle of coverage of sample 14 the block 10 reaches the highest value, and when the disk makes a half turn, it decreases to zero, and the sample 14 returns to the initial position under the action of the spring 2O. 14 to the other side by block 11. This device, as a result of replacing the reciprocating movement in the mechanism for creating a cyclic load on the continuous rotation, allows an increase in the frequency of the voltage and, consequently, the performance of the test. Claims 1. A device for testing flexible fatigue samples, comprising a base, a sample pre-tensioning mechanism located thereon, a spring-loaded grip associated therewith, rollers around the sample end sections, a cyclic load mechanism and a dynamometer, characterized in that In order to improve the performance of the test, the SRI mechanism for creating a cyclic load is made in the form of a rotating disk, a bar pivotally mounted on a disk with eccentricity relative to it. axis and two units with parallel axes arranged on the bar, between which a gap is formed for the test sample. 2. A device according to claim 1, characterized in that, in the bar longitudinal slots are made for the installation movement of the blocks thereto. Sources of information, p {5in t into consideration during the examination 1. Author's certificate of the USSR 10O753, cl. Q O1 N 3/34, 1954. 2. USSR author's certificate number 178553, cl. G 01 N 3/34, 1964 (prototype). but H, ttlH-)