SU1097913A1 - Device for material fretting wear testing - Google Patents

Abstract

A DEVICE FOR TESTING MATERIALS FOR WEAR FROM THRINGTING, comprising a body, a vibromachine, a sample holder, a counterbeam holder fixed to the body, and a static sample loading unit, different from the fact that, in order to expand the range of amplitudes during testing, it is equipped membrane mounted on the working body of the vibratory machine perpendicular to the direction of its movement, the node of the amplification of excitation of oscillations, made in the form of an elastic element with interchangeable weights placed on the membrane, and connected to erzhatelem sample.

Description

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6 to 1 The invention relates to the testing of materials for wear under the conditions of their vibration tangential relative displacements. A device for testing materials for wear from f.retting is known, which contains a vibrating machine, a housing, a sample holder attached to the working member of the vibrating machine, a sample holder mounted on the housing, and a static loading unit Cl3. A disadvantage of the known device is the small range of amplitudes achieved during testing. An increase in amplitudes during tests on this device requires an unrealistic increase in power consumption and mass of the vibrator. The purpose of the invention is to expand the amplitude range during the tests. The goal is achieved by the device for testing materials for fretting wear, comprising a body, a vibratory machine, a sample holder, a holder of contrasons mounted on the body, and a static loading unit of the samples, provided with a membrane fixed to the working body of the vibrating machine perpendicular to the direction of its movement , by an oscillation enhancement unit made in the form of an elastic element with interchangeable weights placed on the membrane and connected to the sample holder. Figure 1 shows the scheme of the proposed device; Fig. 2 is a diagram of the interaction of masses and elastic elements of the device. The device contains a vibrating machine 1 mounted on the working body of the vibrating machine body 2, in which the contra-specimens 3 and unit 4 are placed for static loading. The working body of the vibratory machine 1 is connected through the membrane 5 to the holder 6 of sample 7. On the membrane 5 there is a fixed excitation amplification unit, made in the form of elastic elements 8 with removable weights 9. To determine the pressing force of the ends 3 to the sample's wearing surfaces 7, the static loading unit has dynamometric elements 10. The holder 6 of sample 7 may include a dynamometer 11 to determine the force exciting the oscillations of the sample 7. The test is carried out at elevated temperatures and the installation is equipped with heating devices 12 m, which can be accomplished, for example, in the form of furnace or inductor for high-frequency heating. Induction heating can also be used for tests during thermal cycling. In this case, the installation is additionally equipped with air nozzles for cooling:} The working area (not shown). For tests at higher temperatures, the holder 6 and the static loading unit 4 are made cooled. . The device works as follows. The fretting wear test is carried out in a resonant mode. In the absence of contact between sample 7 and contrails 3, the installation represents a three-mass oscillatory system (Fig. 2). Mass M ,. includes the mass of the working body of the vibratory machine 1, body 2, unit 4 of static loading and part of the mass of the membrane 5, Mass M, consists of part of the mass of the membrane 5, mass of the holder 6 with sample 7 and part of the mass of the elastic element 8. Part of the mass of the elastic element 8 and the mass of removable weights 9 constitutes the mass M. The mass M2 is connected to the masses M and M and M by the stiffnesses of the elastic element C of Special Feature C 2, respectively. The main feature of the three-mass system is that the mass M, on which the contra-edge is fixed, and the mass M2 with the sample fixed on it during oscillations in the first form move in antiphase. If the contrasts 3 are pressed to sample 7 and there is no slippage between them, then the system approaches a two-mass one with masses M and M M, ... By increasing the excitation force, it is possible to obtain the required amplitude of relative displacements of the sample 7 and counter-specimens 3 for a given pressing force . The oscillation frequency of a system with slippage is somewhat higher than that of a three-mass without slippage, however, the modes of oscillation are close to that shown in Fig. 2. The resonant frequency of the entire three-mass system can be perished due to a change in the mass of the weights 9 (K -i).

Depreciation is determined after operating time under given loading conditions. a certain number of cycles according to the results of holding the sample 7 and counter samples 3 or according to profilograms of m.

The invention allows an increase in the displacement amplitudes compared

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with realizable with forced oscillations. Performing the installation in the form of a three-mass oscillatory system makes it possible to increase the amplitude of the relative displacements by providing oscillations of the sample and contra-samples in antiphase, which, in turn, expands the technical capabilities of the device.

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Claims (1)

DEVICE FOR TESTING MATERIALS FROM FRETTING, comprising a body, a vibrating machine, a sample holder, a sample holder mounted on the body, and a static loading unit for samples, characterized in that, in order to expand the amplitude range during testing, it is equipped with a membrane mounted on the working body of the vibrator is perpendicular to the direction of its movements, the unit for amplifying the excitation of vibrations, made in the form of an elastic element with interchangeable weights placed on the membrane, and connected to the holder sample. Up /