CN116976077A - Method and system for evaluating uncertainty of measurement result of metal tensile test - Google Patents
Method and system for evaluating uncertainty of measurement result of metal tensile test Download PDFInfo
- Publication number
- CN116976077A CN116976077A CN202310678950.9A CN202310678950A CN116976077A CN 116976077 A CN116976077 A CN 116976077A CN 202310678950 A CN202310678950 A CN 202310678950A CN 116976077 A CN116976077 A CN 116976077A
- Authority
- CN
- China
- Prior art keywords
- uncertainty
- tensile
- upper yield
- elongation
- measurement
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005259 measurement Methods 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000009864 tensile test Methods 0.000 title claims abstract description 27
- 239000002184 metal Substances 0.000 title claims abstract description 18
- 239000007769 metal material Substances 0.000 claims abstract description 26
- 238000012360 testing method Methods 0.000 claims abstract description 20
- 238000011156 evaluation Methods 0.000 claims description 5
- 230000008439 repair process Effects 0.000 claims description 4
- 239000006185 dispersion Substances 0.000 abstract description 7
- 238000009827 uniform distribution Methods 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 3
- 238000013178 mathematical model Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Health & Medical Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Geometry (AREA)
- Evolutionary Computation (AREA)
- Computer Hardware Design (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a method and a system for evaluating uncertainty of a metal tensile test measurement result, wherein the method comprises the following steps: obtaining an uncertainty source of tensile strength, upper yield strength and elongation of a metal material tensile test; and calculating uncertainty averages of a plurality of tensile strengths, uncertainty averages of a plurality of upper yield strengths and uncertainty averages of a plurality of elongations of the metal material according to the uncertainty sources. The uncertainty of measurement assessed by the present invention derives from the dispersion of data obtained from different tests, different testers or different laboratories extracted from the metallic material and does not describe the dispersion caused by the inhomogeneities of the metallic material, the assessment of which is more accurate and reliable than the data obtained with only one test, one tester or laboratory.
Description
Technical Field
The invention relates to the technical field of evaluation methods for measuring uncertainty, in particular to a method and a system for evaluating uncertainty of a measurement result of a metal tensile test.
Background
Metal mechanical property measurements when a standard is measured with a measurement system or instrument, the measurement results often deviate to some extent from the true values. The reasons for these deviations are described as an uncertainty value, which is evaluated in the prior art by using only one test, one test machine or laboratory to obtain data, which is not accurate and reliable.
Aiming at the problems of inaccurate and unreliable assessment in the prior art, no effective solution is proposed at present.
Disclosure of Invention
The embodiment of the invention provides a method and a system for evaluating uncertainty of a metal tensile test measurement result, which are used for solving the problems of inaccurate and unreliable evaluation in the prior art.
In order to achieve the above object, in one aspect, the present invention provides a method for evaluating uncertainty of a measurement result of a metal tensile test, the method comprising: obtaining an uncertainty source of tensile strength, upper yield strength and elongation of a metal material tensile test; and calculating uncertainty averages of a plurality of tensile strengths, uncertainty averages of a plurality of upper yield strengths and uncertainty averages of a plurality of elongations of the metal material according to the uncertainty sources.
Optionally, the source of uncertainty in the tensile strength includes: repeatability, maximum force, original cross-sectional area of sample, and draw rate were measured.
Optionally, the uncertainty source of the upper yield strength includes: repeatability, upper yield force, original cross-sectional area of sample, and rate of stretching were measured.
Optionally, the uncertainty source of the elongation includes: repeatability of measurement, original gauge length of sample, elongation after break, and repair.
Optionally, the uncertainty of the maximum force or the upper yield force includes: uncertainty caused by indication errors of a force measuring system of the testing machine, relative standard uncertainty of a standard force measuring instrument and relative standard uncertainty caused by a computer data acquisition system.
Optionally, the uncertainty of the original cross-sectional area of the sample includes: the uncertainty introduced by the measurement width and the uncertainty introduced by the measurement thickness.
Optionally, the uncertainty of the tensile strength is calculated according to the following formula:
wherein R is m For tensile strength, rep is the measurement repeatability, F m Is the maximum force, S 0 R is the original cross-sectional area of the sample mv To influence the tensile strength by the tensile Rate, u rel Is uncertainty.
Optionally, the uncertainty of the upper yield strength is calculated according to the following formula:
wherein R is eH For the upper yield strength, rep is the measurement repeatability, F eH For the upper yield force S 0 R is the original cross-sectional area of the sample mHv To influence the tensile Rate on the upper yield Strength, u rel Is uncertainty.
Optionally, the uncertainty of the elongation is calculated according to the following formula:
wherein A is elongation, rep is measurement repeatability, deltaL is elongation after break, L 0 For the original gauge length of the sample, off is reduced, u rel Is uncertainty.
In another aspect, the present invention provides a system for assessing uncertainty in a metal tensile test measurement, the system comprising: the acquisition unit is used for acquiring uncertainty sources of tensile strength, upper yield strength and elongation of the metal material in a tensile test; and the calculating unit is used for calculating uncertainty average values of a plurality of tensile strengths, uncertainty average values of a plurality of upper yield strengths and uncertainty average values of a plurality of elongation of the metal material according to the uncertainty source.
The invention has the beneficial effects that:
the invention provides a method and a system for evaluating uncertainty of a metal tensile test measurement result, wherein the method comprises the following steps: obtaining an uncertainty source of tensile strength, upper yield strength and elongation of a metal material tensile test; and calculating uncertainty averages of a plurality of tensile strengths, uncertainty averages of a plurality of upper yield strengths and uncertainty averages of a plurality of elongations of the metal material according to the uncertainty sources. The uncertainty of measurement assessed by the present invention derives from the dispersion of data obtained from different tests, different testers or different laboratories extracted from the metallic material and does not describe the dispersion caused by the inhomogeneities of the metallic material, the assessment of which is more accurate and reliable than the data obtained with only one test, one tester or laboratory.
Drawings
FIG. 1 is a flow chart of a method for evaluating uncertainty of a measurement result of a metal tensile test according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a measurement result uncertainty evaluation system for a metal tensile test according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Metal mechanical property measurements when a standard is measured with a measurement system or instrument, the measurement results often deviate to some extent from the true values. The reasons for these deviations are described as an uncertainty value, which is evaluated in the prior art by using only one test, one test machine or laboratory to obtain data, which is not accurate and reliable.
Thus, the present invention provides a method for assessing uncertainty in a measurement result of a metal tensile test, wherein the uncertainty in the measurement assessed by the present invention is derived from the dispersibility of data obtained from different tests, different testers or different laboratories extracted from a metal material, and does not describe the dispersion caused by the non-uniformity of the metal material, and the assessment is more accurate and reliable than the data obtained from one tester or laboratory using only one test. Fig. 1 is a flowchart of a method for evaluating uncertainty of a measurement result of a metal tensile test according to an embodiment of the present invention, as shown in fig. 1, the method includes:
s101, obtaining uncertainty sources of tensile strength, upper yield strength and elongation of a metal material tensile test;
s102, calculating uncertainty averages of a plurality of tensile strengths, uncertainty averages of a plurality of upper yield strengths and uncertainty averages of a plurality of elongations of the metal material according to the uncertainty sources.
(1) Sources of uncertainty in the tensile strength include: repeatability, maximum force, original cross-sectional area of sample, and draw rate were measured.
The mathematical model of tensile strength is: r is R m ＝F m /S 0 ；
(1) Measurement of the uncertainty in the standard due to repeatability u rel (rep) evaluation of the terms:
the uncertainty of the average of the measurements of the three samples is evaluated by the class A method, and should be divided by
(2) Maximum force F m Relative standard uncertainty term u rel (F m ) Assessment of (2)
Uncertainty u of the maximum force rel (F m ) Comprising the following steps: uncertainty u caused by indicating value error of force measuring system of testing machine rel (F 1 ) Relative standard uncertainty u of standard dynamometer rel (F 2 ) Relative standard uncertainty u brought by computer data acquisition system rel (F 3 )。
a. Uncertainty u caused by indicating value error of force measuring system of testing machine rel (F 1 )
The error of the indication value of the electronic tensile testing machine is +/-1.0%, and the electronic tensile testing machine is considered according to uniform distributionThen:
b. relative standard uncertainty u of standard force gauge rel (F 2 )
The testing machine was identified using a standard load cell of grade 0.3, with r=0.3% given in JJG 144-2017. Its relative standard uncertainty is:
c. relative standard uncertainty u brought by computer data acquisition system rel (F 3 )
The uncertainty of class B relative to the standard introduced by the computer data acquisition system is 0.2% as given in the JF1103-2016 metering specification.
u rel (F 2 )＝0.2％
Thus, the relative standard uncertainty term u of maximum force rel (F m )
(3) Relative uncertainty term u of original cross-sectional area of sample rel (S 0 ) Assessment of (2)
Uncertainty u of original cross-sectional area of the sample rel (S 0 ) Comprising the following steps: measurement of uncertainty u introduced by width a rel (a) Measurement of uncertainty u introduced by thickness b rel (b)。
According to the GB/T228-2021 standard, when measuring the original cross-sectional area, each dimension should be measured to be accurate to + -0.5%.
S 0 ＝ab
u rel (S 0 )＝u rel (a)+u rel (b)
a. Measuring uncertainty introduced by width a
b. Measuring uncertainty introduced by thickness b
U is then rel (S 0 )＝u rel (a)+u rel (b)＝0.578％
(4) Relative standard uncertainty term u due to the influence of the stretching rate rel (R mv ) Assessment of (2)
The tensile strength is different by 10MPa in the change range of the stretching rate, so that the influence of the stretching rate on the tensile strength is +/-5 MPa, and the following uniform distribution is considered:
in summary, the relative resultant uncertainty in tensile strength is shown in the following table:
the uncertainty of the tensile strength is calculated according to the following formula:
wherein R is m For tensile strength, rep is the measurement repeatability, F m Is the maximum force, S 0 R is the original cross-sectional area of the sample mv To influence the tensile strength by the tensile Rate, u rel Is uncertainty.
(2) Sources of uncertainty in the upper yield strength include: repeatability, upper yield force, original cross-sectional area of sample, and rate of stretching were measured.
The mathematical model of the upper yield force is: r is R eH ＝F eH /S 0
Uncertainty u of the upper yield force rel (R eH ) Comprising the following steps: uncertainty caused by indication errors of a force measuring system of the testing machine, relative standard uncertainty of a standard force measuring instrument and relative standard uncertainty caused by a computer data acquisition system.
The calculation process of the upper yield strength is the same as that of the tensile strength, and the calculation process is omitted. The data after calculation and statistics are shown in the following table:
the uncertainty of the upper yield force is calculated according to the following formula:
wherein R is eH For the upper yield strength, rep is the measurement repeatability, F eH For the upper yield force S 0 R is the original cross-sectional area of the sample mHv To influence the tensile Rate on the upper yield Strength, u rel Is uncertainty.
(3) Sources of uncertainty in the elongation include: repeatability of measurement, original gauge length of sample, elongation after break, and repair.
The mathematical model of the elongation is:
wherein A is elongation, L 0 For the original gauge length of the sample, L u The post-breaking gauge length of the test specimen.
(1) Measuring relative standard uncertainty term u caused by repeatability rel Assessment of (rep)
The uncertainty of the average of the measurements of the three samples is evaluated by the class A method, and should be divided by
(2) Class B relative uncertainty term u for original gauge length of sample rel (L 0 ) Assessment of (2)
The marks L of the original gauge length being specified by standards 0 Should be accurate to + -1%. Considered as uniform distributionThen:
(3) class B relative standard uncertainty term u for elongation after break rel Assessment of (ΔL)
Elongation after break (Δl=l u -L 0 ) To a measurement of + -0.25 mm. The average elongation of this test is 15.598, considered in terms of uniform distributionThen:
(4) relative standard uncertainty term u brought by digital reduction rel Assessment of (off)
The gap between the elongation after break and the repair is about 0.5%. The relative standard uncertainty term brought by the reduction is considered according to the uniform distribution:
in summary, the relative synthetic uncertainty of the elongation is shown in the following table:
the uncertainty of the elongation is calculated according to the following formula:
wherein A is elongation, rep is measurement repeatability, deltaL is elongation after break, L 0 For the original gauge length of the sample, off is reduced, u rel Is uncertainty.
In an alternative embodiment, the method further comprises: extended uncertainty
95% confidence level, k=2 total spread uncertainty example
99% confidence level, k=3 total spread uncertainty example
Fig. 2 is a schematic structural diagram of a system for evaluating uncertainty of measurement results of a metal tensile test according to an embodiment of the present invention, as shown in fig. 2, the system includes:
an acquisition unit 201 for acquiring uncertainty sources of tensile strength, upper yield strength, elongation of the metallic material tensile test;
a calculating unit 202 for calculating an uncertainty mean of a plurality of tensile strengths, an uncertainty mean of a plurality of upper yield strengths, and an uncertainty mean of a plurality of elongations of the metal material according to the uncertainty source.
The invention has the beneficial effects that:
the invention provides a method and a system for evaluating uncertainty of a metal tensile test measurement result, wherein the method comprises the following steps: obtaining an uncertainty source of tensile strength, upper yield strength and elongation of a metal material tensile test; and calculating uncertainty averages of a plurality of tensile strengths, uncertainty averages of a plurality of upper yield strengths and uncertainty averages of a plurality of elongations of the metal material according to the uncertainty sources. The uncertainty of measurement assessed by the present invention derives from the dispersion of data obtained from different tests, different testers or different laboratories extracted from the metallic material and does not describe the dispersion caused by the inhomogeneities of the metallic material, the assessment of which is more accurate and reliable than the data obtained with only one test, one tester or laboratory.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for evaluating uncertainty of a measurement result of a metal tensile test, comprising:
obtaining an uncertainty source of tensile strength, upper yield strength and elongation of a metal material tensile test;
and calculating uncertainty averages of a plurality of tensile strengths, uncertainty averages of a plurality of upper yield strengths and uncertainty averages of a plurality of elongations of the metal material according to the uncertainty sources.
2. The method according to claim 1, characterized in that:
sources of uncertainty in the tensile strength include: repeatability, maximum force, original cross-sectional area of sample, and draw rate were measured.
3. The method according to claim 2, characterized in that:
sources of uncertainty in the upper yield strength include: repeatability, upper yield force, original cross-sectional area of sample, and rate of stretching were measured.
4. The method according to claim 1, characterized in that:
sources of uncertainty in the elongation include: repeatability of measurement, original gauge length of sample, elongation after break, and repair.
5. A method according to claim 3, characterized in that:
uncertainty of the maximum or upper yield force includes: uncertainty caused by indication errors of a force measuring system of the testing machine, relative standard uncertainty of a standard force measuring instrument and relative standard uncertainty caused by a computer data acquisition system.
6. A method according to claim 3, characterized in that:
the uncertainty of the original cross-sectional area of the sample includes: the uncertainty introduced by the measurement width and the uncertainty introduced by the measurement thickness.
7. The method according to claim 2, characterized in that:
the uncertainty of the tensile strength is calculated according to the following formula:
wherein R is m For tensile strength, rep is the measurement repeatability, F m Is the maximum force, S 0 R is the original cross-sectional area of the sample mv To influence the tensile strength by the tensile Rate, u rel Is uncertainty.
8. A method according to claim 3, characterized in that:
the uncertainty of the upper yield strength is calculated according to the following formula:
wherein R is eH For the upper yield strength, rep is the measurement repeatability, F eH For the upper yield force S 0 R is the original cross-sectional area of the sample mHv To influence the tensile Rate on the upper yield Strength, u rel Is uncertainty.
9. The method according to claim 4, wherein:
the uncertainty of the elongation is calculated according to the following formula:
wherein A is elongation, rep is measurement repeatability, deltaL is elongation after break, L 0 For the original gauge length of the sample, off is reduced, u rel Is uncertainty.
10. A metal tensile test measurement uncertainty evaluation system, comprising:
the acquisition unit is used for acquiring uncertainty sources of tensile strength, upper yield strength and elongation of the metal material in a tensile test;
and the calculating unit is used for calculating uncertainty average values of a plurality of tensile strengths, uncertainty average values of a plurality of upper yield strengths and uncertainty average values of a plurality of elongation of the metal material according to the uncertainty source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310678950.9A CN116976077A (en) | 2023-06-08 | 2023-06-08 | Method and system for evaluating uncertainty of measurement result of metal tensile test |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310678950.9A CN116976077A (en) | 2023-06-08 | 2023-06-08 | Method and system for evaluating uncertainty of measurement result of metal tensile test |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116976077A true CN116976077A (en) | 2023-10-31 |
Family
ID=88475709
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310678950.9A Pending CN116976077A (en) | 2023-06-08 | 2023-06-08 | Method and system for evaluating uncertainty of measurement result of metal tensile test |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116976077A (en) |
-
2023
- 2023-06-08 CN CN202310678950.9A patent/CN116976077A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Motra et al. | Assessment of strain measurement techniques to characterise mechanical properties of structural steel | |
| CN110411836B (en) | Test and calculation method for measuring plastic strain ratio of metal material | |
| CN109855583B (en) | Method for determining uncertainty of measurement of three-coordinate measuring machine | |
| CN111751313A (en) | Method for evaluating measurement uncertainty of single-point calibration measurement system | |
| Ling et al. | A new method for selection of population distribution and parameter estimation | |
| CN110031281B (en) | Method for determining steel type | |
| CN109870354B (en) | Automatic measurement method for elongation after uniaxial tension fracture of metal round bar sample | |
| CN116976077A (en) | Method and system for evaluating uncertainty of measurement result of metal tensile test | |
| CN111539953B (en) | Method for detecting depth of decarburized layer of steel | |
| CN107451408B (en) | Coal-fired heating value data checking method | |
| CN108195339B (en) | Uncertainty determination method for plate flatness measurement result in field environment | |
| CN104407222A (en) | Method for measuring electrical resistivity of irregular small-section copper bar material | |
| CN112505215A (en) | Method for evaluating uncertainty of content of octabromodiphenyl ether in sample | |
| CN113155011A (en) | Protective layer thickness detection method based on environmental calibration | |
| CN113008679B (en) | Creep rate measuring method based on endurance test | |
| US4081994A (en) | Method of tension stress testing of rubber | |
| CN111366281A (en) | Method for detecting accuracy of residual stress by XRD (X-ray diffraction) method and calculating shear stress | |
| CN108534918A (en) | Automatic isolation detection system of sensor | |
| KR102508885B1 (en) | Method for measuring the elongation of thick steel plate | |
| Koepke et al. | Using Monte Carlo Methods to Compute the Uncertainty of Fracture Toughness and Fracture Resistance Curves | |
| CN109342405A (en) | The detection method of wax oil nitrogen content | |
| JPH063238A (en) | Method for calculating tensile elastic modules in extensiometer | |
| CN118837197A (en) | Method, system and equipment for measuring yield strength by adopting micro sample | |
| CN115497198B (en) | Uncertainty evaluation method for fuel consumption of commercial vehicle | |
| CN115856006A (en) | Method for measuring ductile-brittle transition temperature of oriented silicon steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |