SU1516870A1 - Installation for mechanical tests of materials in axial cyclic loading - Google Patents

Abstract

The invention relates to installations for the mechanical testing of samples of materials, mainly rocks, under axial cyclic loading. The purpose of the invention is to expand the functionality by providing both single-cycle and two-cycle loading, as well as three-cycle loading with independent control of the frequency of cycles and the limits of load variation for each cycle. The installation comprises a base 1 with a guide 2, traverses 3,4 and grippers 5 for sample 6, a power spring 7 and a deformation mechanism 23, a loading screw 8 connected kinematically with the drives 9-11, and mechanisms for cyclic movement of the loading screw 8: the mechanism of reciprocating movement of the nut 12, the mechanism of reciprocating rotation of the load screw 8 in the form of a worm gear pair 15,16, associated with the drive 9, the mechanism 17,18 of reciprocating movement of the screw screw 16, a reciprocating rotation mechanism scheni worm screw 16 in the form of worm pairs 19,20, 21,22 through the eccentric fixture associated with the actuator 11. To test if one-, two- or three-cycle loading include one or two in any combination or drive all three drive. 1 il.

Description

and two-cycle loading and three-cycle loading with independent regulation of the frequency of cycles and the limits of load variation for each cycle. The installation comprises a base 1 with a guide 2, traverses 3, 4, and grippers 5 for sample 6, a power spring 7 and a mechanism for its deformation 23, a loading screw 8, kinematically connected with the drives 9-11, and mechanisms for cyclic movement of the loading screw 8 : reciprocating mechanism of the nut 12, -the mechanism of reciprocating movement of the load pint 8 in the form of a worm gear pair 15, 16, connected with the drive 9. mechanism 17, 18 of the reciprocating movement of the worm screw 16, reciprocating rotational mechanismeremescheni worm screw 16 in a worm pair 19, 20 by

an eccentric device 21, 22 connected to the drive 11. For tests with one-, two- or three-cyclic loading, include one or two in any combination of drive or

all three drives. 1 il.

The invention relates to the testing of materials, in particular to installations for testing specimens under axial cyclic loading.

The purpose of the invention is to extend the functionality by providing both single-cycle and two-cycle loading, as well as three-cycle loading with independent control of the frequency of the cycles.

The drawing shows the installation diagram, a general view.

The installation comprises a base 1 with a guide 2. two movable cross braces 3 and 4 with grippers 5 for sample 6, a cyclic loading mechanism including a power spring 7 and a loading screw 8, kinematically connected with the drives 9-11.

The installation is equipped with a nut 12 mounted on the load screw 8 and cooperating with the guide 2 so that it can only perform axial movement, the mechanism of reciprocating movements of the nut 12 including the frame 13 fixed on the nut 12. and the eccentric 14 mounted on the drive shaft 10, the mechanism of reciprocating rotation of the load screw 8, including a 1m worm gear pair in the form of a worm gear 15 mounted on the shank of the load screw 8, and a worm gear 16, kinematically connected with the drive 9, eccentric mechanism of the reciprocating movement of the worm screw 16, including the frame 17 and the eccentric 18 mounted on the drive shaft 9, the mechanism of the reciprocating rotary movement of the worm gear

screw 16, including a second worm pair in the form of a wheel 19 mounted on a screw screw 16, and screw 20 interacting with an eccentric device, frame 21 of which is fixed on a screw screw 20, and eccentric 22 on a shaft

the drive 11, and the traverse movement mechanism 23. 3 along guide 2.

The installation works as follows.

To test sample 6 under single-cycle loading, one of the mechanisms is actuated, for example, actuator 10, and through the eccentric 14, the frames 13 move the nut cyclically

12, which leads to cyclic axial movements of the loading screw 8, deformation of the spring 7 and cyclic loading of the sample with 6 axial force.

For testing a sample under two-cycle loading, any second drive of mechanisms is included — for example, drive 11. At the same time, the eccentric 22 moves the screw 20 cyclically in the axial direction of the screw 20 and by turning the wheel 19 rotates the screw 16 cyclically. rotation of the wheel 15 and the reciprocating axial movements of the load

screw 8 when interacting with the nut 12.

The test of the sample under tricycle loading includes the third drive 9 of the installation and, by means of the eccentric 18, the frame 17 and the screw 16 with the wheel 15, cause reciprocating movement of the load piece 8. All three loading cycles

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can be created simultaneously, alternately and in any combination, have a different frequency, controlled by the speeds of rotation of the eccentrics of the respective mechanisms. The average load on the specimen is set and adjusted during the test by the screw mechanism 23 by changing the deformation of the spring 7.

The loading mode is selected in cor correspondence with the mode of operation of the sources of cyclic loading in nature with the corresponding loading frequencies and phase shifts. The limits of load variation for each cycle are controlled by eccentricity of eccentrics and stiffness of the power spring.

Claims (1)

Invention Formula An apparatus for mechanical testing of materials under axial cyclic loading, comprising a base with a guide, two movable crossbars with grips for the specimen mounted on it, a cyclic loading mechanism including a loading screw, a kinematically connected drive of rotation, a power spring interacting with one of the traverse, and the mechanism of deformation force 70 springs, characterized in that, in order to expand the functional possibilities by providing both single-cycle and two-cycle loading, and three-cycle loading with independent regulation of part-cycles, it is equipped with two additional rotational drives, mounted on the base, with a nut mounted on load screw and made with a hole through which the guide passes, the mechanism of reciprocating axial movement of the nut associated with one of the additional drives of rotation, mechanical measuring the reciprocating movement of the load screw in the form of a worm wheel mounted on its shank and a worm screw interacting with it, kinematically connected with the main drive of rotation, a worm screw reciprocating mechanism mounted on the main drive shaft, and the mechanism of reciprocating movement of the screw screw, made in the form of a second screw pair, the wheel of which is mounted on the screw screw, and the device for reciprocating moving the screw screw of this pair connected to the shaft of the second auxiliary drive.