SU1370513A1 - Method of testing material specimens for twisting - Google Patents

Abstract

The invention relates to the testing of materials and makes it possible to evaluate the fatigue strength of materials under alternating torsion. A sample that has, at the ends of the working section, intersecting bars with longitudinal axes perpendicular to the axis of the working section, applies a load by sliding two semi-cylinders along opposite edges of the respective bars. The load is applied by reciprocating the half-cylinders, and before each loading cycle the sample is rotated 90 degrees around the axis of the working section. 4 il.

Description

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This invention relates to material testing.

The aim of the invention is to provide 4eiffle the ability to evaluate fatigue strength with alternating torsion.

FIG. 1 shows a diagram of the first sample loading cycle; in fig. 2 shows section A-A in FIG. one; in fig. 3 is a diagram of the second loading cycle; in fig. 4 shows a section BB in FIG. 3

The method is carried out as follows.

A load is applied per sample of the sample, which has crossing stitches 2 and 3 with longitudinal axes perpendicular to the axis of the working part 1, at the ends of the working part 1. The load is created by moving along the axis, perpendicular to the axis of the working part of the sample, two semi-cylinders A and 5, sliding along opposite edges 6.8 and 7.9 of the respective bars 2 and 3. As the load increases, the working part 1 undergoes twisting deformation, the value of which depends on the load R.

At a given amount of deformation of the twisting of the working part 1, the force P is released, the semicylinders 4, 5 are retracted from the sample, and the latter is rotated 90 around the axis of the working part 1 and the second loading cycle is performed. For this, the sample is loaded with semicylinders 4 and 5, ensuring their sliding along opposite edges 10,12 and 11,13. In this case, the working part 1 is subjected to the twisting deformation of another sign, i.e. aus132

There is an alternating cyclic loading of the working part of the sample by reciprocating movement of the half-cylinders 4 and 5 and rotating the sample by 90 around the axis of the working part 1 before each loading cycle.

Depending on the purpose of the experiment, the test was carried out until the working part 1 of the sample was destroyed or a predetermined residual strain accumulated in it, while fixing the number of sample loading cycles. The sample can be rotated even after the sample passes a specified number of loading cycles with a torque of one sign.

Formula of the invention

A method for testing material samples in torsion, which consists in applying a load perpendicular and the axis of the working part perpendicular to the longitudinal axis of the working part to the sample that is created by moving along the axis perpendicular to the working part of the sample. , two semi-cylinders sliding along opposite edges of the respective bars, characterized in that, in order to enable evaluation of the strength of the alternating torsion, the load is applied by moving the half-cylinders, and before each cycle, rotate the sample by 90 around the axis of the working part.

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Claims (1)

20 claims A method of testing material samples for torsion, namely, that a load is applied to a sample having crossing bars with longitudinal axes perpendicular to the axis of the working part at the ends 25 of the working part, which are created by moving two half-cylinders along the axis perpendicular to the 30 working part of the sample sliding along opposite sides of the corresponding bars, characterized in that, in order to provide the ability to 35 assess fatigue strength in alternating torsion, the load is applied by the reciprocating movement of the half-cylinders, and before each cycle they turn, a sample of 90 ° around the axis of the working part. Fig 3 6-δ R <... J G- rV . 7 i 1 R FIG. 4