SU976338A1 - Device for break-testing flat samples having notch - Google Patents

Description

The invention relates to testing equipment, in particular to clamping devices of testing machines.

A device for tensile testing specimens containing wedge liners with stops and Cl clamps is known.

The disadvantage of this device is that the clamping device is not matched with the tops of the clamping jaws. This prevents the sample from having a minimum area of rupture.

The closest to the invention to the technical essence is a device for tensile testing of flat samples with a notch to the testing machine, containing two pairs of cylindrical vertically detachable clamping jaws with a truncated cone at the apex, in one of which there is a recess in the plane of the split; the other has a protrusion C2 entering it.

A disadvantage of the known device is that the tops of the clamping jaws are not conjugated in the plane of the above-cut sample. As a result, the stress concentration at the top of the notch is not high enough, which leads to a curved fracture surface. The consequence is a lack of accuracy and reproducibility of the test results.

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The aim of the invention is to improve the accuracy of the test results.

This goal is achieved by the fact that, in a tensile testing device for flat samples with a notch to a testing machine, containing two pairs of cylindrical, vertically detachable tightening jaws with a truncated cone at the apex, in one of

Claims (2)

20 of which are flat (; the bones of the connector have a recess, and the other has a protrusion into it, the tops of the clamping jaws are mated in the incision plane, and the dotted cones form an annular groove of a triangular cross section with an apex angle equal to 120-160. Besides In addition, the device is equipped with an elastic element placed in an annular recess and connected to the grippers of the testing machine. Figure 1 shows a general view of the device, a section; Figure 2 shows the same collection, the Device contains detachable clamping jaws 1 and 2 truncated cone 3 at the top 4. Clamping sponge There is a recess 5, and a sponge 2 a protrusion 6, a case for placing a sample (not shown) between the spacers 7. The truncated cones 3 form a recess 8. The device also contains an elastic element 9 connected to the grip of the testing machine in the form of a sleeve 10 and an annular punch 11 and, moreover, fastening elements 12 placed in the holes 13. The device works as follows. The sample with gaskets 7 is placed in the recess 5 of the clamping jaw 1 and with the jaw 6 of the clamping jaw 2, then the assembly is connected by fasteners 12 in such a way that the tops of the clamping jaws are in contact, and the truncated cones 3 form an annular recess 8 in which an elastic ring 9. is placed. Thus assembled, the device is placed in the cage 10 and is loaded by means of a punch 11. The force from the punch 11 is transferred to the forming truncated cones 3 and through fasteners 12 to the test sample. After testing, the device is disassembled in reverse order. Thus, the advantages of the proposed device in comparison with the known ones is to increase the accuracy of the test results, since the system of securing the sample in the clamping jaws, due to the curvature of the fracture surface, eliminates additional errors. Improving the accuracy of the test results is due to the fact that the tops of the clamping jaws mate in the notch plane, and the truncated Cone form an annular groove of a triangular cross section with an apex angle of 120-160 °, and it is provided with an elastic element. Such a notched loading pattern allows the specimen to be destroyed along the surface coinciding with the plane of the tops of the clamping jaws. These factors contribute to the accuracy of the test results. Claim 1. A device for tensile testing of flat specimens with a notch to a testing machine, comprising two pairs of cylindrical, vertically detachable jaws with a truncated cone at the apex, in one of which there is a recess in the plane of the connector and another in its protrusion is about the fact that, in order to increase the accuracy of the test results, the tops of the clamping jaws are mated in the notch plane, and the truncated cones form an annular recess of a triangular cross-section with an angle of is not equal to 120-160 °. 2. The device of clause I, clause 1, and the fact that it is provided with an elastic element located in the annular recess and associated with the grippers of the testing machine. Sources of information taken into account in the examination 1. USSR author's certificate number, cl. G 01 N C / O, 1976. 2. USSR author's certificate number 532033, cl. G 01 N C / O, 1972 (prototype). nV YU M FIG. one...