RU2400731C1 - Installation for testing samples of materials for fatigue - Google Patents

Abstract

FIELD: machine building. ^ SUBSTANCE: installation for testing samples of materials for fatigue consists of base, of two coaxial sample grippers mounted on base, of rotating shaft installed coaxially to grippers and travelling along axes of grippers, of rotary bushing positioned on base coaxial to shaft and of pendulum hinged with shaft and bushing. Additionally, there is a rotary driven platform installed on the base and a roller positioned parallel and coaxial to the platform and interacting with the pendulum. Also a stop is arranged on the end of the pendulum for interaction with the platform. The roller is equipped with a drive for axial displacement relative to the platform. ^ EFFECT: extended volume of obtained information due to possibility to test sample loading it under mode of specified limits of change of mutually alternating sign-changing axial and torsion forces and under mode of attenuating limits of these loads change. ^ 1 dwg

Description

The invention relates to testing equipment, to strength tests.

A known installation for testing fatigue of samples of materials (RF patent No. 1629811, class G01N 3/32, 1989) containing a base, two coaxial grippers for a sample placed on it, a shaft mounted coaxially with grippers for rotation and axial movement, and a pendulum connected to the shaft.

The disadvantage of the installation is that it is not feasible tests when loading the sample in the mode of specified limits of change of alternating axially and torque loads mutually alternating and in the mode of decaying limits of change of these loads. Tests are carried out only in decaying mode and without mutual change of axial and torque loads.

A known installation for testing fatigue of samples of materials (RF patent No. 1739261, class G01N 3/32, 1989) containing a base, two coaxial grippers for a sample placed on it, a shaft mounted coaxially with grippers for rotation and axial movement, and a pendulum articulated to the shaft.

The disadvantage of the installation is that it is also not feasible tests when loading the sample in the mode of given limits of change of alternating axially and torque loads mutually alternating and in the mode of decaying limits of change of these loads.

A known installation for fatigue testing of samples of materials (RF patent No. 2050538, class G01N 3/32, 1994), taken as a prototype. The installation comprises a base, two coaxial grippers for the sample placed on it, a shaft mounted coaxially with the grippers for rotation and axial movement, a sleeve placed on the base coaxially with the shaft for rotation, and a pendulum pivotally connected to the shaft and with the sleeve.

The disadvantage of the installation is that it is also not feasible tests when loading the sample in the mode of given limits of change of alternating axially and torque loads mutually alternating and in the mode of decaying limits of change of these loads. Tests are carried out only at decaying load limits and without mutual load changes.

The technical result of the invention is to increase the amount of information obtained by providing tests during loading of the sample in the mode of specified limits of change of alternating axially and torque loads mutually alternating and in the mode of decaying limits of change of these loads.

The technical result is achieved by the fact that the installation for testing fatigue of samples of materials containing a base, two coaxial grippers for the sample placed on it, a shaft mounted coaxially to the grippers with the possibility of rotation and movement along the axis of the grippers, a sleeve placed on the base coaxially with the shaft with rotation , and a pendulum pivotally connected to the shaft and with the sleeve, according to the invention, a platform with a rotation drive is installed on the base, a roller mounted parallel and coaxial to the platform and designed for interaction with the pendulum, while at the end of the pendulum a latch is mounted for interaction with the platform, and the roller has a drive for axial movement relative to the platform.

With such changes in the setup, the pendulum can make forced circular motions or circular motions with a damping amplitude, which gives loading to the sample in the mode of specified limits of change of alternating axially and torque loads mutually alternating or in the mode of decaying limits of change of these loads. This is not feasible on the prototype and provides a technical result.

The drawing shows the installation diagram.

The fatigue testing apparatus for samples of materials contains a base 1, two coaxial grippers 2, 3 placed on it for sample 4, a shaft 5 mounted coaxially with the grippers for rotation and movement along the axis of the grippers, a sleeve 6 placed on the base coaxially with the shaft for rotation , and the pendulum 7, pivotally connected with the shaft 5 and with the sleeve 6.

A platform 8 with a rotation drive 9, a roller 10 mounted parallel and coaxial to the platform 8 and designed to interact with the pendulum 7 is installed on the base. At the end of the pendulum 7, a latch 11 is mounted for interaction with the platform 8.

The roller 10 has a drive 12 for axial movement relative to the platform 8.

Between the gripper 2 and the shaft 5, an elastic element 13 is installed for transmitting a torque load to the specimen, and a spring loader 14 is used to create the axial load. The gripper 3 has no rotational movement, but has the possibility of axial movement, which is ensured by connecting it to the base with a polyhedron 15. On the weight of the pendulum 7 is set 16. The sleeve 6 is fixed to the base with a nut 17. A hole 18 is made in the sleeve, the pendulum 7 passes through this hole to provide articulation.

Installation works as follows.

To load the sample 4 in the mode of set limits, mutually alternating alternating axial and rotational loads include a latch 11 and connect the end of the pendulum 7 to the platform 8, turn on the drive 9 and rotate the platform 8. The pendulum 7 makes circular movements around the roller 10 and creates axial and rotational movements shaft 5. The shaft 5, when rotated through the elastic element 13, creates torsional forces on the sample 4, and during axial movements creates axial forces on the sample using a loader 14. To load the sample 4 in the mode of decaying interactions but alternating axial and twisting loads alternating, the latch 11 is turned off, after which the pendulum rotates around the roller by an angle by inertia, then, due to the elastic properties of the sample material and elements 13, 14, makes a reverse rotation by a smaller angle, and so on, until the stored kinetic rotation energy. To resume loading in the mode of the set limits of the load changes, the latch 11 is turned on again. To adjust the limits of the load changes, the drive 12 moves the roller 10, change the angle of inclination of the pendulum 7 to the platform 8 and thereby change the limits of rotation and axial displacements of the shaft 5.

The installation provides tests in new conditions - when loading a sample in the mode of specified limits of change of mutually alternating axially and torque loads and in the mode of decaying limits of change of these loads.

Claims (1)

An installation for testing fatigue of samples of materials, containing a base, two coaxial grippers for the sample placed on it, a shaft mounted coaxially to the grippers to rotate and move along the axis of the grippers, a sleeve placed on the base coaxially with the shaft to rotate, and a pendulum articulated with a shaft and with a sleeve, characterized in that on the base there is a platform with a rotation drive, a roller mounted in parallel and coaxial to the platform and designed to interact with the pendulum, At the end of the pendulum, a latch is mounted to interact with the platform, and the roller has a drive for axial movement relative to the platform.