SU1022040A1 - Method and device for checking metal article stressed deformed state - Google Patents

Abstract

1. A method for monitoring the strain-induced state of metal products, which consists in exciting eddy currents in the surface layer of the product, removing the alternating current signal from the measuring winding of the converter, and determining the internal voltage of the product, which is about 1 L and in order to increase the reliability of the control, a direct current is supplied to the exciting winding of the converter and, simultaneously with the measurement of the AC signal, a change is made Resistance (L of the excitation winding to the direct current and from it determine also the deformation of the product. To 1C

Description

P 2. A device for controlling the stress-strain state of metal products, comprising a flat flexible winding whose coils are extended in the direction of one axis, and a substrate made of an elastic magneto-electrician in which the winding is attached so that the magneto-dielectric covers only long

side of the winding, characterized in that, in order to increase the reliability of the control, it is equipped with an additional winding, identical in shape and located respectively with it, and one of the windings is made of a high resistive stress-sensitive alloy.

This invention relates to methods. non-destructive testing and is designed to study the stress-strain state of metal products of complex shape.

A known method for monitoring the stress-strain state of metal products is that a strain gauge is installed on the controlled area of the product and the deformation of product C is determined by changing the current flowing through it.

The disadvantage of the method is the low reliability of the results when measuring the internal stresses of the products.

LIAH.

The closest to the technical essence of the invention is a method of controlling the stress-strain state of metal products, which consists in that eddy currents are excited in the surface layer of the product, the AC signal is removed from the measuring winding of the converter and according to the results of its harmonic analysis determine the value of the internal voltage of the product C2,

A device for implementing this method comprises a flat flexible winding, the turns of which are extended in the direction of one axis, and a substrate of elastic magnetodielectric to which the winding is attached in such a way that the magnetodielectric covers only the long side of the winding C3Q.

The disadvantages of the method and device for its implementation are the lack of information Q of the actual strains and, as a result, the low reliability of the control.

The aim of the invention is to increase the reliability of the control.

The goal is achieved by the fact that, according to the method of control of the stress-strain state

metal products, which means that in the surface layer of the product excites eddy currents, remove the AC signal from

About the measuring winding of the transducer and the results of its harmonic analysis determine the value of the internal for 1p of the product, on the excitation winding of the transducer

5, DC is supplied and simultaneously with the measurement of the AC signal, the change in resistance of the exciting winding to the direct current is measured and it is also determined

0 and the deformation of the product.

A device for controlling the stress-strain state of metal products, comprising a flat flexible winding, the coils of which are extended in the direction of one axis, and a substrate of elastic magnetodielect, the riic to which the winding is attached so that the magnet-dielectric covers only the long sides of the MOTC , is equipped with an additional winding, identical in shape and located coaxially with it, and one of the windings is made of a high-resistance tensically sensitive alloy. Fig. 1 shows the construction of a converter; in fig. 2 - winding structure; Fig. 3 is a diagram for implementing the method.

The Converter contains the exciting winding 1 and the measuring winding 2, located on the substrate 3 of the elastic magnetodielectric.

BiiiepAbt C and 5 of winding 1 and pins 6 and 7 of winding 2 are used for switching the windings with the lithium and measuring circuit. The transducer is attached to the surface 8 of the monitored product 5 by means of glue seam 9. The short sides 10 and 11 of windings 1 and 2 in the transducer are folded back onto the opposite surface of the substrate 3, in lines А-А and В-в .. Windings 1 and 2 to represent identical flat spiral flexible windings made of metal foil according to printing technology. The exciting winding is powered by a generator 15 12. At the same time, a constant electric voltage is supplied to the exciting winding 1 and by means of a measuring bridge 13 constant Nogo current is determined -change ee.omi- 20 moskogo resistance. The measuring winding 2 is connected to the harmonic analyzer 14, the output of which and the bridge 13 are connected to the indicator 15.

The method is implemented as follows:

P "13OM-. : -; -

. An alternating current signal from the generator is supplied to the excitation winding 1 of the transducer attached to the surface 6 of the test article. The exciting winding 1 induces eddy currents in the surface layer of the product to be controlled,

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the change in the characteristics of which is determined by the value of the controlled parameter — the effective mechanical stresses in the product. The field of eddy currents is recorded by measuring winding 2, the output signal of which is fed to the analyzer 1 harmonics 5 | where the amplitude-phase harmonic analysis of the signal is performed.

At the same time, a constant electric voltage is applied to the exciting winding 1 and a change in its ohmic resistance determined by the magnitude of the deformations acting in the product is recorded, for which the winding 1 is included in the measuring bridge 13 constant current circuit. The output signals of the analyzer I and the bridge 13 are fed to the indicator 15.

When implementing this method, the converter may be included in the differential circuit together with an additional converter mounted on the reference sample.

MS invention invention to be used for operational control of the strength of large-sized metal products in the course of their operation in the construction, engineering, aviation and shipbuilding industries.

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Claims (1)

1. A method for monitoring the stress-strain state of metal products, which consists in the fact that eddy currents are excited in the surface layer of the product, the AC signal is taken from the measuring winding of the transducer, and the value of the product’s internal voltage is determined from the results of its harmonic analysis, which correlates with I mean that, in order to increase the reliability of control, a direct current is supplied to the exciting coil of the converter and, simultaneously with the measurement of the AC signal, a change in resistance windings of the exciting winding to direct current and from it also determine * the deformation of the product. _"And SU 1022040 f 2. An apparatus for controlling the stress-strain state of metal products, comprising a flat flexible coil turns which vytyanuty'v one axis direction, and a substrate of flexible magnetodielectric, wherein the coil is fixed in such a manner that covers only Magnetodielectrics long sides windings, characterized in that, in order to increase the reliability of control, it is equipped with an additional winding, ideally first in shape and located accordingly with it, and one of the windings is made of high eye-strain-sensitive alloy.