SU588486A1 - Apparatus for mechanical testing of curvilinear specimens - Google Patents

Description

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The invention relates to the field of physical and mechanical testing of materials and is intended for mechanical testing of curved samples.

At present, a device for mechanical testing of curvilinear samples, made in the form of grips with a cylindrical bearing surface, whose curvature corresponds to the curvature of the test sample 1, is known.

However, on such devices it is impossible to test samples with different curvature.

The closest solution to the invention is a device for mechanical testing of curvilinear specimens, comprising a copier with a supporting surface for mounting the specimen and two levers fitted with grippers and connected to each other by means of a hinge 2.

The disadvantages of such a device are the need for a large number of interchangeable patterns for each type of curvature, as well as the fact that the test load is not applied tangentially to the sample curvature.

In order to enable testing of samples with different curvature in the proposed device, the copier is made in the form of a package of bolted plates with a through hole, one side of which forms a bearing surface,

at the same time, the middle plate interacts with a length-adjustable stop connected to the hinge of the levers.

FIG. 1 shows an insulated device, general view; in fig. 2 - the same, top view.

A device for mechanical testing of curvilinear specimens contains a package of plates 1 with through holes for test sample 2 and two elongated holes for fastening bolts 3, 4.

One side of the through-hole for the test specimen is rounded and forms a bearing surface. The surfaces of the plates have a small notch to increase friction between two adjacent plates. Extreme and middle plates are thicker than others.

Tension bolts 3 and 4 fix the plates in a certain position. The elements are a copier.

The device also contains two levers 5 and 6, connected together with each other by a hinge 7, also connected with a length 8 adjustable in length.

The free ends of the arms are studs 9, 10 for the grippers of the testing machine and, using bolts 11, fix the grippers 12 to fasten the test sample 2.

The operation of the device is as follows.

By adjusting the length of the stop 8, an approximate radius of curvature of the sample 2 is established. By loosening the nuts, bolts 3, 4 are loosened. Sample 2 is passed through the notches in the plates 1 and its ends are fixed by the grippers 12. Then the plates are moved relative to the fixed sample and are tightened with the bolts 3, 4, which ensures the preservation of the curvature of the sample during the test.

The device is fastened in the grips of the test pattern, through which a loading force is transmitted to it, causing destruction of the sample and fixed by the mask indicator.

Since the force applied by the machine is divided into two: the compressive levers and the tangential force on the sample, the force applied to the sample must be determined by the formula:

N, to

where is the force on the sample;

Lm - the force recorded by the indicator of the testing machine;

L is half the distance between the grips along the chord;

 - Radius of sample curvature. Such an embodiment of the device, unlike the known ones, allows testing samples of different curvature, which eliminates the need to manufacture a large number of CMieHHbix patterns for each type of curvature, as well as apply a load that is strictly tangential to the curvature of the sample.

Claims (2)

1. Certificate of author No. 172531, cl. G 01/03/1961. 2. The copyright certificate number 345404 Cl. G 01p 3/04, 1972. IG one