SU1589115A1 - Method of determining tensile strength of materials - Google Patents

Abstract

The invention relates to a testing technique and can be used to determine the strength of materials under tension. The purpose of the invention is to simplify the tests by identifying the sample destroyed at the time of the tensile stress jump. Several samples 1-5 are placed in the same plane and at equal distances from each other. Samples 1-5 are fixed in common grips 6 and 7 so that they undergo the same deformation during the test. Along the edges of one of the grips (gripper 6), force-measuring devices 8 and 9 are placed, and the samples are loaded with a constant velocity. The tensile force from the energizer is applied to the grips via force-measuring devices 8 and 9. When loading, the deformation of the samples and the tensile force are recorded according to the indications of the force-measuring devices. The loading is carried out before the successive destruction of the samples. The fracture stresses of various samples are judged by the magnitudes of the jumps in the tensile stress, and the fracture deformations by the strain values corresponding to the indicated jumps. The identification of the sample destroyed during the tensile stress jump is performed taking into account the relationship of the forces recorded on each of the load cells at the time of the destruction. 7 il.

Description

1

one

The invention relates to a test technique and can be used to determine the strength of materials under stretching.

The purpose of the invention is to simplify the tests by identifying the sample destroyed at the time of the tensile stress jump.

FIG. 1 shows a set of samples before failure, - FIG. 2 - FIG. 5 successive destruction of samples; in fig. 6 is a design diagram for identifying samples; in fig. 7 change in reading P, force meter 8,

I The method is carried out as follows.

Several samples (Fig. 1 shows five samples 1-5) are located in the same plane and at equal distances from each other. Samples 1-5 are fixed in the common grippers 6 and 7 so that they undergo the same deformation during the test.

Along the edges of one of the grips (gripper 6 in Fig. 1), force measures B and 9 are placed.

Samples 1–5 are stretched at a constant rate. The tensile force from the energizer (not shown) is applied to the grippers through force-measuring devices 8 and 9.

When loading, the deformation of the samples and the force P and P are recorded, and the streams according to the readings of load cells 8 and 9 (Fig. 2 shows a diagram of the force P of load cells 8 - the strain of the sample). The loading of events is carried out until successive destruction

samples.

The fracture forces of various samples are judged by the magnitude of the jumps of the tensile stress (Fig. Shows the jumps. LR} -, dp J; / 3,; 4P f; effort Р ,, recorded by force meter 8, a similar diagram is used for indications second strength tester), and about deformations of destruction - by values 1,,, “and deformations corresponding to the indicated jumps. The identification of the sample destroyed during the tensile stress jump is performed taking into account the relationship of the forces recorded at each of the load cells at the time of destruction.

For example, if, when the sample is 3 broken, the readings of Measuring Instruments 8 and 9 are the same, then

ten.

With the subsequent break of sample 1, we have

 7/11.

With subsequent breaks of samples and 5, we have:

, (

and;

FS7 / n (5)

PV / P 7 - 5/7 and 2.

The order of the gap may be different, then the sequence of relations between the indications of the force meters will be different, but specific for each order.

Claims (1)

Invention Formula The method of determining the strength of materials under stretching, in which several samples are placed in the same plane and at equal distances from each other, is fixed to the samples in common grips so that they undergo the same deformation during the test, load the samples with a constant velocity from the energizer through common grips, they continuously record with the help of sensors the tensile force applied to the grips and the deformation of the samples, and the forces of destruction of various samples are judged by jump values in the tensile stress, and on the fracture deformations - in terms of the strain values corresponding to the indicated jumps, characterized in that, in order to simplify the tests by identifying the sample destroyed at the moment of the tensile stress, two force meters are used, which are located along the edges one of the grippers, where the first and the last specimen is fixed, respectively, the tensile force from the energizer is applied to the grips. Through force meters, and the identification of the sample being destroyed during the tensile force jump, n by considering relations effort recorded on each of Cu lovozbuditeley fracture point. u well Figg LA L k F Fig.Z t 111 sh well FIG. J Sh HLb; Tt FIG 5 f 2 J 5 a a o F F F F F FIG. 6 R, Shig 1