GOST R 55047-2012

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  ГОСТ Р 55047-2012

GOST R 55047−2012 Technical diagnostics. Nonstandard calibration of measurement equipment for diagnosing the stress-strain state of structural materials. General requirements

GOST R 55047−2012

Group Т59

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Technical diagnostics

NONSTANDARD CALIBRATION OF MEASUREMENT EQUIPMENT FOR DIAGNOSING THE STRESS-STRAIN STATE OF STRUCTURAL MATERIALS

General requirements

Technical diagnostics. Without standards calibration of equipment for measuring the stress-strain state of structural materials. General requirements

OKS 77.040.10

Date of introduction 2014−01−01

Preface

1 DEVELOPED by Autonomous non-commercial organization «Scientific-research center of control and diagnostics of technical systems» (ANO «nits KD»), a limited liability company «Energodiagnostika» (LLC «Energodiagnostika»)

2 SUBMITTED by the Technical Committee for standardization TC 132 «Technical diagnostics"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology dated November 8, 2012 N 700th St

4 INTRODUCED FOR THE FIRST TIME


Application rules of this standard are established in GOST R 1.0−2012 (section 8). Information about the changes to this standard is published in the annual (as of January 1 of the current year) reference index «National standards» and the official text changes and amendments — in monthly information index «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in the upcoming issue of the monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet (www.gost.ru)

Introduction

Currently intensively developed and increasingly implemented in engineering practice methods of diagnosing of stress-strain state of structural materials critical technical objects based on modern methods of nondestructive testing.

Most of the methods of nondestructive testing of stress-strain state involves the use of calibration of the used measuring instruments on the samples (usually samples tensile).

At the same time, we know that such a calibration often leads to significant errors in determining the stress-strain state of structural elements of the real hardware that does not meet the stress-strain state of the calibration samples.

The creation of a common reference samples for comparison of different NDT methods for stress taking into account the scale factor, the nature of workloads and locality zones of maximum stresses is not possible.

In these circumstances, a standard that sets General requirements to the procedure nonstandard calibration of measuring instruments used in the diagnosis of stress-strain state of structural materials using nondestructive methods.

1 Scope

This standard covers means of diagnosis of the stress-strain state of structural materials that use non-destructive testing methods applicable at the time of manufacturing, and operation of critical technical objects.

The standard establishes General requirements to the procedure nonstandard calibration of measuring instruments for determining mechanical stresses in the material of technical objects under the action of workloads.

The standard does not apply to the determination of residual stresses arising in irreversible changes of the material due to heat treatment, plastic deformation, fatigue damage accumulation, etc.

2 Normative references

This standard uses the regulatory references to the following standards:

GOST 12.1.019−79 System of standards of occupational safety. Electrical safety. General requirements and nomenclature of types of protection

GOST 12.1.038−82 standards System of labor safety. Electrical safety. The maximum permissible values of the touch voltage and currents

GOST 18353−79 nondestructive testing. Classification of types and methods

GOST 21616−91 strain Gages. General specifications

GOST 21625−76 Device information-measuring digital, with a string transducer for measuring linear dimensions

GOST 23479−79 nondestructive testing. Methods optical. General requirements

GOST 28836−90 force measuring strain gauge Sensors. General technical requirements and test methods

GOST R 52330−2005 non-destructive Control. Control of the stress-strain state of objects of industry and transport. General requirements

GOST R 52731−2007 nondestructive testing. Acoustic method of control of mechanical stresses. General requirements

GOST R 52890−2007 nondestructive testing. Acoustic method of control of stresses in material of pipelines. General requirements

GOST R 52891−2007 Control of technological residual stresses by laser interferometry. General requirements

GOST R 53204−2008 nondestructive testing. Acoustic method of control of variable mechanical stresses. General requirements

GOST R 53966−2010 nondestructive testing. Control of the stress-strain state of the material structures. General requirements to the procedure for the choice of methods

GOST R ISO 24497−2-2009 nondestructive testing. The method of metal magnetic memory. General requirements

GOST R ISO 24497−3-2009 nondestructive testing. The method of metal magnetic memory. Part 3. Weld inspection

Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet or in the annual information index «National standards» published as on January 1 of the current year, and the editions of the monthly information index «National standards» for the current year. If replaced with a reference standard, which was given an undated reference, then it is recommended to use the current version of this standard, taking into account all enabled in this version modifications. If replaced with a reference standard, which is given a dated reference, it is recommended to use the version of this standard referred to above by year of approval (acceptance). If after approval of this standard in the reference standard, which is given a dated reference, a change affecting a provision to which reference, the provision is recommended to be applied without taking into account this change. If the reference standard is cancelled without replacement, the position in which reference is made to him, recommended to be used in part not affecting this link.

3 Symbols and abbreviations

3.1 this standard applies the following abbreviations:

VAT — intense-deformed condition;

EOPO — of the object of industrial hazards;

NDT — non-destructive testing;

OIS — the object of tests;

SI — a means of measurement.

4 General provisions

4.1 the selection of SI for diagnosis of VAT material EOPO guided by the requirement of maximum sensitivity of the applied NDT methods.

4.2 the choice of NDT methods proceed from the General requirements to the procedure of selecting the churchyard R 53966.

4.3 Recommended to use the following methods according to GOST 18353:

4.3.1 Strain gauge method GOST 52728* using the following types of strain gauges:

________________
* Probably, the error of the original. Should read: GOST R 52728. — Note the manufacturer’s database.

— electrosensory 21616 according to GOST 28836 and GOST;

mechanical strain gauges [1];

optical strain gauges;

— string strain gauges, devices, information-measuring digital, with string converters according to GOST 21625.

4.3.2 Magnetic methods based on the measurement of the following parameters:

— Barkhausen noise;

— coercive force;

— magnetic anisotropy;

— magnetic field scattering (method of magnetic memory of metal) according to GOST R ISO 24497−2 and GOST R ISO 24497−3.

4.3.3 optical Methods of GOST 23479, including:

interferometric method according to GOST R 52891;

— method of moire stripes;

— method of optically sensitive coatings.

4.3.4 x-ray method.

4.3.5 Acoustic methods based on the phenomenon of customproperty:

— methods that use bulk elastic (longitudinal and transverse) waves in accordance with GOST R 52731, 52890 GOST R and GOST R 53204;

methods using elastic surface waves of Rayleigh [2];

— methods that use an elastic head (crawling, subsurface, in foreign literature — wave) [3].

4.4 Requirements EOPO and means of diagnosis of VAT must provide possibility of implementation established by this standard procedure, nonstandard calibration.

4.5 the Basis for the selection OI in the calibration means of diagnosing the VAT should be the analysis of the results conducted by the manufacturer, AOPA experimental studies of conformity VAT of the material or and EOPO or analysis of the results of practical application of selected methods to the same objects.

4.6 the manufacturer, AOPA, operating, EOPO, as well as the enterprise engaged in the diagnosis of EOPO shall have normative and technical documents on selected NDT method and means of diagnosis of VAT and to have appropriately qualified professionals.

5 General requirements to order nonstandard calibration of measurement equipment for diagnosing the stress-strain state

5.1 When nonstandard calibration set directly on the real EOPO by comparing the results of the control VAT, obtained by the action of workloads and after their withdrawal.

Note — as of OI in the calibration means of diagnosing VAT can be used models of simulating working conditions of real EOPO given scale factor.

5.2 the choice of method MK and the calibration of the SI for the diagnosis of VAT should be guided by GOST R 52330.

5.3 selecting OI for calibration of diagnosis of VAT you need to consider the locality of control and the area (volume) averaging in the assessment of VAT AOPA.

5.4 keep the speed of loading OI from minimum load to maximum . It is recommended to provide at least five levels of load for the subsequent regression analysis of test results.

Note — depending on the kind of EOPO load can be pressure, force, bending moment, etc.

5.5. install the sensors calibrated SI.

5.6 At each stage of loading carried out measurements of the parameters of the method of the NC, implemented by the calibrated SI. Each stage loads (in the order «up-down») is repeated three times.

5.7 Calculate the linear regression coefficients of dependence of values of method parameters NC from load, using the method of least squares.

5.8 this standard is applicable if the correlation coefficient for 5.7 not less than 0.9.

5.9 based On the data for 5.7 and 5.8 build calibration curves or making the coefficients of the linear regression in database SI.

5.10 an Example of a nonstandard calibration of SI for diagnosis of VAT of the material of the pipeline by an acoustic method is given in Appendix A.

6 security Requirements

6.1 the execution of works on calibration of measuring devices for diagnosing VAT construction materials, AOPA allow operators with skills of operation of the chosen means of diagnosis of VAT, capable of using normative and technical documents on relevant NDT trained to work with used C and are certified for knowledge of safety regulations in the relevant sector of industry.

6.2 the Operator shall abide by the rules of technical safety for operation of electroinstallations of consumers 12.1.019 GOST and GOST 12.1.038.

Annex a (informative). An example of a nonstandard calibration of measurement equipment for diagnosing the stress-strain state of the material of the pipeline by an acoustic method

Appendix A
(reference)

A. 1 In accordance with the current experimental data the classical formula of customproperty [2, 4, 5] gives satisfactory results for structural materials that do not possess a high anisotropy of mechanical properties. To them are applicable the methods for determining stresses by the acoustic method, regulated by GOST R and GOST 52731 R 52890 identifying necessary customplugin coefficients for elastically deformable flat samples the churchyard 1497.

A. 2. In common cases, when the tubing material has a pronounced anisotropy of the mechanical properties (an example is steel controlled rolling), the use of classical formulas of customroot leads to unacceptable errors in the determination of stresses in the material of the pipeline due to the incorrect use of certain flat calibration samples provocations coefficients [6].

A. 3: Increased precision of determining the stresses in material of pipelines made of an anisotropic material can be achieved by using for calibration the acoustic method of tube samples, geometric parameters which correspond to parameters expected to survey pipelines.

A. 4 calibration as OU used a sample made of pipe steel, controlled rolling, X70, with a diameter of 1420 mm, thickness 20 mm, length 8 m, sealed at the ends.

Two zones were established groups of piezoelectric converters providing a radiation and reception of bulk longitudinal and transverse waves to determine the biaxial stress state in accordance with GOST R and GOST 52731 R 52890.

A sketch of the sample is shown in figure A. 1.

Figure A. 1 — Tube sample for calibration of an acoustic method for the determination of the stress state

1 — cut tubing; 2, 3 — hermetic plug; 4 — nipple; 5 — manometer; 6 — zone of dimension (N 1 and N 2)

Figure A. 1 — Tube sample for calibration of an acoustic method for the determination of the stress state

A. 5 To create pressure through the nozzle 4 in the region of interest was re-injected water. The pressure was controlled with a pressure gauge 5.

A. 6 In tables A. 1-A. 4 shows the measurement results of the delays of pulses of elastic waves of various types, propagating perpendicular to the sample surface. In the tables the following designations are used:

—  — pulse delay of the shear wave with polarization parallel to the axis of the sample;

—  — pulse delay of the shear wave with polarization perpendicular to the axis of the sample;

—  — delay pulse longitudinal waves;

— is the pressure determined by pressure gauge 5;

— ring voltage is calculated according to the formula

, (A. 1)

where the inside diameter of the sample;

 — the wall thickness of the sample;

 — the axial stress of the investigated OI associated with ring voltage ratio

. (A. 2)

In the tables , , , correspond to the unstressed condition of the material , .


Table A. 1 — Zone N 1, the growth pressure

Table A. 2 — Area N 1, the pressure reduction

Table A. 3 — Area N 2, the growth pressure

___________________
* Consistent with the original. — Note the manufacturer’s database.


Table A. 4 — Area N 2, the pressure reduction

A. 7 as the equations of customroot use generalized equations:

, (A. 3)

, (A. 4)

where , , ,  — provocations the coefficients material with arbitrary anisotropy.

A. 8 the results of the measurements are given in A. 6, provocations allow us to determine the coefficients , , , in accordance with the following procedure.

A. 8.1 the System of equations (A. 3-A. 4) is considered as two linear regression models:

, (A. 5)

. (A. 6)

A. 8.2 the Coefficients , , , are determined by the method of least squares. Each of the equations (A. 5) and (A. 6) is a special case of multiple regression equations without intercept functions on variables :

, (A. 7)

where the  — parameters regression number independent variable is the number of the measurement.

A. 8.3 Estimation of regression parameters is carried out by the method of least squares, which minimize the quadratic form

, (A. 8)

which leads to a system of equations linear with respect to the regression parameters :

. (A. 9)

A. 8.4 In this case, the problem of estimating provocations coefficients is reduced to solving a system of two linear equations:

, (A. 10)

. (A. 11)

A. 8.5 the Solution of the system of equations (A. 10-A. 11) has the form:

, (A. 12)

. (A. 13)

A. 8.6 Thus, expressions to define provocations coefficients , , , are of the form:

— for , :

, , , , ;

— for , :

, , , , .

A. 9 After averaging the results given in tables A. 1-A. 4, we obtain a table of source values to calculate provocations coefficients.


Table A. 5 — table of source values to calculate the coefficients provocations

___________________
* Consistent with the original. — Note the manufacturer’s database.

A. 10 Using the data of table A. 5 in the calculation procedure given in A. 8, we obtain the following values of the coefficients provocations:

Of 1.32 X10MPa, -3,11х10MPa,

0,37х10MPa, -8,52х10MPa.

A. 11 To check the correctness of the obtained results was carried out measurement of stress in a zone spaced at a distance of approximately 1 m along the axis of the sample from zone No. 2.

The measurements were carried out under the same pressure values as in the calibration process.

The results of measurements of acoustic characteristics and stress analysis are given in table A. 6, where values and correspond to the axial and circumferential stresses, calculated according to the formulas (A. 3), (A. 4), and  — the absolute error of their determination.


Table A. 6 — Results of experimental verification of the computational method

The results given in table A. 6, show a relatively high precision of determining the stresses in the investigated region of interest.

Bibliography

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