SU953517A1 - Device for testing materials for faticue in biaxial extension - Google Patents

Description

(54) INSTALLATION FOR TESTS MATERIALS FOR TIRED TIRES AT BILATERAL EXTENSION

one

The invention relates to the testing of the strength properties of materials, namely, devices for determining the fatigue properties of materials during biaxial stretching.

A device for testing materials under biaxial loading is known, which contains a loading mechanism, is arranged in a mutual mechanism. but perpendicular to the grip for attaching the fl 3 sample.

The disadvantage of the installation is that its use does not provide fatigue tests for biaxial stretching over a programmed load cycle.

Closest to the invention by technical essence is a biaxial fatigue testing apparatus, containing 20 grippers for fastening a specimen, arranged in mutually perpendicular directions, and loading mechanism, executed in the form of a parallelogram.

the link of which is open at the vertices lies on one of its diagonals and is connected to the energizers 2.

The disadvantage of the device is that it does not allow testing of materials according to a given program.

The purpose of the invention is to conduct tests on a programmed load cycle.

Claims (1)

This goal is achieved by the fact that in a device for testing materials for fatigue with biaxial stretching containing grippers for fastening a sample, which are located in mutually perpendicular directions and loading MexaHHavi, the loading mechanism includes an elastic ring that interacts with the external surface with the grips of the sample, rotor, bearing radially located sliders with pressure-bearing rims aI placed at their ends, in contact with the inner surface of the elastic ring, mounted on the rotor shaft between sliders with POSSIBILITY rotational and axial perematseii kschshovoy expansible element ymezyuschy various UTTKh iiaioioHa its working planes and apparatus for imparting axial oscillations of the latter. In addition, the device for communication. The axial oscillations in the wedge expansion element are made in the form of an end cam mounted on the rotor shaft, and a spring-loaded pusher interacting with it, which is mounted on the wedge expansion element. FIG. 1 depicts the proposed installation, longitudinal section} in FIG. 2, section A-A in FIG. one; on phagg. 3 - installation option. The installation includes a housing 1, a loading mechanism including a drive 2 providing a predetermined speed of rotation of the shaft 3 with the rotor 4. Inside of which are mounted a wedge expansion element 5 having the shape of a truncated four-sided pyramid, and sliders 6 with pressure rollers 7 contacting with the inner surface an elastic ring 8, which with its external surface interacts with the grips 9 of sample 10, mounted in the direction 11 of the shaft 11. On the shaft 3 is placed a device for communicating axial vibrations to the wedge clamping element, including the end cam 12, fixed by means of a nut 13, and the spring-loaded pusher 14 of the body 15 cooperating with it, which is supported on the wedge expanding element 5. The operating surfaces of the wedge expanding element 5 have different angles of inclination. The elastic ring 8 is attached to the thread slides 16 (Fig. 3) located along the axes of the test sample 10 on its lobes and having the ability to move with the help of screws 17 mounted on the grips 9. The installation works as follows. Sample 10 with grippers 9 are placed in guides 11 of housing 1. Then the elastic ring 8 is put into place so that its outer surface contacts the grippers 9, and the rotor 4 is inserted inside the elastic ring. Rotate the nut 13 to set the specified level of sample loading forces. Drive 2 is turned on and shaft 3 with rotor 4 is accelerated to a predetermined nag frequency already. The end cam 12, rotating with the shaft 3, moves the pusher 14 collately with a predetermined amplitude of overlap. The pusher 14, via the spring 15, transmits the force to the pressure roles 7 of the sliders 6 by means of the wedge fastening element 5. The rollers 7 roll over the inner surface of the pin 8 ,. they deform it and make a wave of radial displacements in it. In this case, cyclic voltages with variable amplitude are generated in the sample due to different angles of inclination of the working planes of the wedge expanding element 5. In particular, the use of the wedge expanding element 5 in the form of a truncated tetrahedral pyramid whose angles of inclination of the planes along the same axis of the test specimen differ from the angles the inclination of the planes located on another axis of the test specimen, allows you to create a voltage in the specimen, the amplitude of which varies twice in one cycle of the installation . By rotating the screws 17 (Fig. 3), the sample 1O is statically loaded with the required force along its axis by compressing the elastic ring 8 in two directions. When rotating the pressure rollers 7 to the position coinciding with the axes of the sample 10, the test sample 1O will be subjected to loading by the pressure rollers 7 by tensile forces equal to those specified on its axis. With further rotation of the pressure rollers by 45 the sample will be exposed to the initial static tension . A device for testing materials for biaxial stretching at a given loading force. permits fatigue testing of materials with an asymmetric loading cycle. Thus, the proposed device allows for fatigue testing of materials under biaxial stretching over a programmed load load cycle. Claims 1. A biaxial fatigue testing apparatus containing a loading mechanism and specimen grippers arranged in mutually perpendicular directions, characterized in that, in order to test the programmed loading cycle, the loading mechanism includes elastic ring, the interaction of the outer surface with the grips of the sample, the rotor, nonsuper radially located sliders with pressure rollers placed at their ends, in contact with the inner enney surface of the elastic ring mounted on a rotor shaft IU ode slides axially movement of ktshnovoy expansible element having different angles of inclination of its working planes, and devices for imparting axial oscillations of the latter. 7 2, Installation according to claim 1, in connection with the fact that the device for communicating axial oscillations to the wedge expansion element is made in the form of an end cam mounted on the rotor shaft and a spring-loaded pusher interacting with it, the spring of which is supported by the wedge element, Ystochngash information taken into account during the examination 1. Author's certificate of the USSR M 413405, cl. QOl N 3/32, 1972. 2, USSR Copyright Certificate Mg 328368, cl. QOlN 3/34, 1967 (phototype). A .6 FIG: I eight ff JO .2.