SU1453157A1 - Method of measuring stresses in parts - Google Patents

Abstract

The invention relates to a measurement technique and can be used to determine stresses in parts of prestressed reinforced concrete, including those under load. The purpose of the invention is to improve the accuracy with unknown physical properties of the part. Part 1 installs a strain gauge 2, fixes its readings, cuts a part near the meter's installation site, installs flexible loader 4 in slot 3, and records the pressure at which the meter measures the initial readings. In this case, before determining the magnitude of the stresses, the above listed operations are carried out on a reference sample loaded with a known load and geometrically identical to the part 1 under investigation with known physical properties. The data obtained are used in determining the magnitude of stresses. 2 Il. SL

Description

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The invention relates to a measurement technique and can be used to determine stresses in parts of prestressed reinforced concrete, including those under load.

The purpose of the invention is to improve accuracy with unknown physical properties of the part.

FIG. 1 shows a diagram of the method implementation, front view; fig 2 is the same side view.

The method is carried out as follows.

A strain gauge 2 is installed on the part 1 (for example, a strain gauge), the readings of the gauge 2 are fixed, the detail 1 is cut near the

the installation location of the meter 2 (cut-off slot 3), install the flexible loader 4 in the slot 3 (for example, from a half-pinhporid tube | and fix the pressure value at

where the meter records the initial indicators.

Before determining the magnitude of the stresses, the listed operations are performed on a loaded, known load-bearing standard sample, geometrically identical to the part 1 under test (with the same arrangement of the strain gauge X, H1 and X depth 3) with known physical properties (made, for example, of aluminum). The load G is effected, for example, by placing the sample on the supports at its ends. The obtained data is used in determining the magnitude of stresses.

Example. The reference is loaded: the sample is voltage 6 and the strain gauge 6 deformation is measured, the reference sample is supplemented by an additional voltage 6, and the voltage G, is measured. At a distance X from the center of the gauge 2, the reference sample is loaded, making a slot 3 with a width HL to a depth of Y, and measuring the E-strain. The reference sample is again loaded with a voltage G ,, measured by h. Take off 6,. The loader 4 is installed in the slot 3, the pressure is raised in it to the value P, and p is measured

Using the obtained data, the refined elastic modulus is determined by one of the formulas

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calibrated coefficient

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calibrated ratio of one. from the fry

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When working with a part in which it is necessary to determine stresses, using the obtained calibration koi K (3- and measured at p and P, determine the elastic modulus of the part

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and the value of the required stresses in the part

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The invention makes it possible to improve the accuracy of determining stresses in a part with unknown physical properties of the material of the part.

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Claims (1)

Invention Formula The method of determining stresses in parts, namely, that a strain gauge is installed on a part, the meter readings are fixed, the detail is cut near the meter location, the meter readings are fixed, a flexible hydraulic loader is installed in the slot, the pressure in the hydraulic loader is increased, and the pressure is fixed, in which the meter records the initial readings, and the measured parameters determine the voltage value, characterized in that, in order to improve the accuracy of the unknown Before determining the magnitude of the stresses, the physical properties of the part carry out the above operations on a reference sample loaded with a known load with known physical properties, 1453157 geometrically identical to the test piece when determining the value of the detail, and the data obtained are used. Fie.2