RU1826034C - Stand for fatigue tests of material specimens - Google Patents

Abstract

The invention relates to testing equipment, in particular to apparatus for testing material samples for strength. The purpose of the invention is to expand the functionality by providing tests not only with bending, but also with torsional load, but also with bending and torsional loads. The installation contains a loader in the form of an inertial load 20. the passive grip 21 of the sample 22 rigidly connected with it, the active grip 23, mounted coaxially with the passive and mounted on the end of the shaft 24 installed in the bearings 25. located in the bushings 18, which are connected

Description

The invention relates to testing equipment, in particular to apparatus for testing material samples for strength.

The purpose of the invention is to expand the functionality by providing tests not only with bending, but also with torsional load, but also with bending and torsional loads.

A positive effect of the invention is that the apparatus provides testing of a sample not only under bending, but also under torsional, but also under bending and torsional loads.

The drawing shows a diagram of the proposed installation.

The apparatus comprises a housing 1, a rotary drive 2 mounted in it in opposite directions of the cranks 3 and 4, snap rings 5 and 6, connected respectively by screws 7 and 8 with axes 9 and 10 and designed to prevent longitudinal displacement of the axes 9 and 10, a connecting rod 11, pivotally connected to a gear rack 12, which is meshed with a gear ring 13 and located in a guide 14, a connecting rod 15, pivotally connected to a pusher 16, to which the brackets 17 are rigidly attached at one end and the other to the corresponding bushings 18 located shown in the grooves 19 of the housing 1, a loader in the form of an inertial load 20, a passive gripper 21 rigidly connected to it 21 of the sample 22, and a coaxial passive active gripper 23 mounted on one end of the shaft 24. The shaft 24 is mounted in bearings 25 located in the corresponding bushings 18 and perpendicular to the grooves 19, passes through an opening in the pusher 16 and is connected to the gear 13 by the other end. The pusher 16 is located in the housing 1 For locking the pusher 16 and the gear rack 12, screws 26 and 27 are used, respectively. Bearings 25 are mounted on the shaft and vtu Ku with interference

Installation works as follows.

For tests in the mode of cyclic change in bending and torsional loads, the radius of the crank 3 is smaller than the radius of the crank 4, or the connecting rod 11 is removed from the gear rack 12, it is locked by the screw 27 and the gear of the axis 9 is disengaged by loosening the screw 7.

or transferring the connecting rod 11 together with the rack 12 and the crank 3 to the new extreme position opposite to the position of the connecting rod 15 (according to the drawing) and gear 9 is engaged, then locking the latter with the screw 7.

Include a drive 2. which leads to a reciprocating and rotational movement of the shaft 24, which performs these movements together with the grippers 23 and 21, the sample 22 and the load 20. In

As a result, the inertial load 20 cyclically loads the sample 22 with both bending and torque loads.

For tests in the cyclic variation of the torque load, the stopper pusher 16 is screw 26, disconnect the connecting rod 15 from the crank 4 and, loosening the screw8, disengage the gear of the axle 10 and then stop the axle This includes the drive 2. which drives the rotary the movement of the shaft 24, while the sample 22 is subjected to the cyclic action of a torque load due to the rotational motion of the inertial load 20.

For cyclic test

changes in the bending load set the same radii of the cranks 3 and 4 and include a drive 2, which with equal speeds moves the reciprocating shaft 24 and the gear rack 12. As a result of the equality of the speeds of translational movement of the gear rack 12 and the gear wheel 13, the last rotation will not receive and the shaft 24 performs only reciprocating movement, while the sample 22

undergoes a cyclic bending load due to the reciprocating motion of the inertial load 20.

The voltage amplitude is controlled by changing the weight of the inertial load 20, changing the radii of the cranks 3 and 4, as well as the location of the connecting rods 11 and 15 in extreme opposite positions.

After the sample is destroyed, the inertial load 20 is held on the shaft 24 by ties 28 made in the form of cables.

Claims (1)

SUMMARY OF THE INVENTION Fatigue testing apparatus for material samples, comprising a housing, a rack-and-pinion mechanism located therein in the form of an engaged gear and rack mounted axially movable, an associated crank mechanism, an inertial load loader rigidly connected with it passive capture of the sample, mounted coaxially with passive active capture, crank mechanism with a pusher placed in the housing with the possibility of axial displacement, and drive, characterized in that, in order to expand functionality by providing tests not only with bending, but also at a torsional load, as well as at a bending and torsional load, the connection of the crank mechanism with the rack-and-pinion mechanism is made in the form of a guide in which the rack gear is located, which is hinged to the crank mechanism, the housing has two grooves, the installation is equipped with two bushings located in the corresponding grooves housings with the possibility of moving along them, with brackets rigidly connected at one end to the pusher, and the other with corresponding bushings mounted perpendicular to the axes of the grooves in the bearings, which are located in the respective bushings, with a shaft at one end of which a gear wheel is fixed, at the other - active grip, and crank mechanisms installed coaxially and connected to the drive.