JJG 145: Evolution and historical versions
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Pendulum Impact Testing Machines
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Verification Regulation of Pendulum Impact Testing Machine
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Standard similar to JJG 145-2011 JJG 145 JJG 1148 JJG 1149 Basic data | Standard ID | JJG 145-2011 (JJG145-2011) | | Description (Translated English) | Special Measuring Tools for Axle Journal in the Railway Rolling Stocks | | Sector / Industry | Metrology & Measurement Industry Standard | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine | JJG 145-2007: Pendulum Impact Testing Machines---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Verification Regulation of Pendulum Impact Testing Machines
National Metrological Verification Regulations of the People's Republic of China
Pendulum impact tester
Published on.2007-08-21
2008-02-21 Implementation
Published by the General Administration of Quality Supervision, Inspection and Quarantine
Pendulum impact tester
Verification Regulations
ImpactTesting
Machines
Replacing JJG 145-1982
This procedure was approved by the General Administration of Quality Supervision, Inspection and Quarantine on August 21,.2007,
Effective February 21,.2008.
Focal unit. National Technical Committee on Hardness and Hardness Measurement
Main drafting unit. Central Iron and Steel Research Institute
China Institute of Metrology
Beijing Institute of Metrology and Testing
Participating drafting unit. Changchun Testing Machine Research Institute
Beijing Nak Analytical Instrument Co., Ltd.
Weapons Department 269 Regional Metrology Station
Shenzhen New Sansi Group Corporation
Shanghai Institute of Metrology and Testing Technology
This Regulation entrusts the National Technical Committee on Strength and Hardness Measurement to be responsible for interpretation
The main drafters of this regulation.
Wang Chunhua (General Research Institute of Iron and Steel)
Zhou Weisong (General Research Institute of Iron and Steel)
Zhang Zhimin (Chinese Academy of Metrology)
Chen Xi (Beijing Institute of Metrology and Testing)
Participating drafters.
Wang Xuezhi (Changchun Testing Machine Research Institute)
Chen Wu (Steel Research Institute)
Wei Yunjian (General Research Institute of Iron and Steel)
Zheng Jianping (Beijing Nak Analytical Instrument Co., Ltd.)
Zhou Zhaofeng (Weapon Department 269 Regional Metrology Station)
An Jianping (Shenzhen Xinsansi Group Company)
Guiren Zhang (Shanghai Institute of Metrology and Testing Technology)
table of Contents
1 Scope (1)
2 Citations (1)
3 Terms and Units of Measure (1)
4 Overview (3)
5 Metrological performance requirements (3)
5.1 Test machine frame (3)
5.2 Pendulum (3)
5.3 Anvil and support (4)
5.4 Indication device (4)
5.5 Indirect verification using standard samples (4)
6 General technical conditions (5)
7 Control of measuring instruments (6)
7.1 Verification conditions (6)
7.2 Verification items (7)
7.3 Verification method (7)
7.4 Available range of testing machine (11)
7.5 Processing of test results (11)
7.6 Verification cycle (11)
Appendix A Standard Impact Specimens of Arc and Rectangle (12)
Appendix B Test Machine Components (14)
Appendix C Impact knife, specimen support and anvil of the testing machine (15)
Appendix D The structure of the sample support and anvil of the working test machine (18)
Appendix E Determination of Initial Potential Energy (19)
Appendix F Verification Certificate Inner Page Format (20)
Appendix G Verification Record of Pendulum Impact Tester (21)
Verification Regulations of Pendulum Impact Tester
1 Scope
This regulation is applicable to the first verification, subsequent verification and in-use inspection of the pendulum impact testing machine (hereinafter referred to as the testing machine).
2 Citations
The following documents are cited in this procedure.
GB/T 229 "Metallic materials-Charpy pendulum impact test method"
GB/T 1043-1993 "Test method for impact of rigid plastic simply supported beams"
GB/T 3808-2002 (ISO 148-2..1998, Metalicmaterials-Charpypendulumimpact
test-Part 2. Verification of test machines, MOD)
GB/T 18658-2002 "Charpy V-notch standard sample for pendulum impact tester inspection"
GB/T 15000.3-1994 "Guidelines for the Work of Standard Samples (3) General Principles and Statistical Methods for the Determination of Standard Samples"
law"
JJG 2077-1990 "Verification System of Pendulum Impact Energy Measuring Instrument"
ASTME23-05StandardTestMethodsforNotchedBarImpactTestingofMetalicMa-
terials
When using this procedure, care should be taken to use the currently valid version of the above-cited references.
3 Terminology and unit of measure
3.1 Terms related to testing machines
3.1.1 Anvilfaces
In the simply supported beam type impact testing machine, it is perpendicular to the horizontal support surface to support the impact of the pendulum on the specimen.
Force bearing surface. Also known as anvil (see Figure C.1)
3.1.2 base
The part of the testing machine frame below the horizontal support surface of the sample support.
3.1.3 centerofpercussion
When the pendulum impacts the specimen, the horizontal impact reaction force of the pendulum axis to the pendulum (refers to the impact reaction force parallel to the upper surface of the sample)
When it is zero, the position of the striking point on the hammer blade. (See Figure D.1).
3.1.4 Hit point centerofstrike
Place the specimen or equivalent gauge with a height of half the standard width (i.e. 5mm) on the specimen support, and the pendulum should be free
In the hanging position, the point where the blade of the impact knife contacts the horizontal plane on the sample (see Figure C.1).
3.1.5 hammering edge
When impacting the sample, the straight part where the hammer blade is in contact with the sample. Sometimes called the impact blade. Actual contact
The blade has a 2mm curvature radius (2mm impact knife) or 8mm curvature radius (8mm impact knife), or other curvature radius
(See Appendix B)
3.1.6 Test piece support
The testing machine base is processed into a horizontal bearing surface, and it is used to place the part that is hit by the pendulum in advance (see figure)
B.1 and Figure C.1). The bearing surface is perpendicular to the bearing surface of the anvil.
3.1.7 industrial testing machine
Testing machines for testing metal materials in industry, general laboratories or most research laboratories. These tests
The machine is not used to give a standard value. The verification of the working test machine shall be carried out in accordance with the methods specified in this Regulation.
3.1.8 reference machine
Testing machine for determining standard energy of standard samples. The verification requirements of this testing machine are stricter than the working testing machine. These ones
The requirements are specified in GB/T 18658.
3.2 Terms related to energy
3.2.1 KV actual absorbed energy (absorbed energy)
When testing with a testing machine, the total energy required to break the sample. It is equal to the initial potential energy of the pendulum in the initial position
The difference from the initial potential energy when the first half cycle is completed after the specimen breaks.
3.2.2 Kp initialpotentialenergy
When the pendulum is in the initial position, it is relative to the horizontal potential energy of the center of mass when the pendulum is in the free position.
3.2.3 Indicated energy (indicated energy)
The energy value indicated by the pointer of the testing machine or other indicating device.
3.2.4 KN nominalinitialpotentialenergy (nominalenergy)
The energy value given by the testing machine manufacturer.
3.2.5 KR reference energy
Absorbed energy value of standard sample.
3.2.6 reference test pieces
Compare the indicated energy measured by the testing machine with the standard energy value marked on the sample to verify the working testing machine
The suitability is used for impact specimens.
3.3 Definition of the sample (test position placed on the support of the test machine) (see Figure D.1).
3.3.1 height
The distance between the notched face and the opposite face.
3.3.2 width
Dimensions parallel to the notch and perpendicular to the height direction.
3.3.3 length
Maximum dimension perpendicular to the direction of the notch.
3.4 Units of measurement
The unit of measurement of pendulum moment M is Newton meters (N · m);
The unit of measurement for impact energy is Joule (J).
4 Overview
4.1 This regulation specifies the verification of a testing machine for the test of a simple supported beam specimen under the action of a single impact force.
method.
4.2 This regulation specifies two verification methods.
a) Direct verification method. This method is actually a static verification method, that is, by examining the key components of the testing machine
To ensure that it meets the requirements of this code. The verification instrument used shall prove that it can be traced to the legal unit of measurement in China.
National benchmark. Also known as component verification method.
b) Indirect verification method. This method is actually a dynamic verification method, that is, a standard sample verification test machine is used.
Also known as indication value verification method.
5 measurement performance requirements
5.1 Test machine frame
5.1.1 The parallelism of the axis of the pendulum axis and the reference plane shall be within 1/1000. The item should be included in the certificate of conformity by the manufacturer
Given.
5.1.2 When the pendulum is suspended freely, the clearance between the blade of the impact knife and the specimen shall be within ± 0.5mm.
5.1.3 The parallelism between the side of the pendulum and the swing plane and the perpendicularity between the side of the pendulum and the specimen support are shown in Table 1.
Table 1 Requirements on the side and swing plane of the pendulum, and the sample support
Impact energy per pendulum/J < 10 ≥10
Parallelism of pendulum side and swing plane 1.5/1000 1.0/1000
The perpendicularity between the side of the pendulum and the sample support is 90 ° ± 0.1 ° (or 3/1000).
5.1.4 The impact blade should be on a plane passing the center of the span of the support and perpendicular to the span, with a tolerance of 0.5mm. Pendulum
When freely swinging, the angle between the blade and the longitudinal axis of the specimen shall be 90 ° ± 2 °.
5.1.5 The axial clearance of the swing shaft should not exceed 0.25mm.
5.1.6 The radial clearance at the swing shaft bearing should not exceed 0.08mm.
5.2 Pendulum
5.2.1 When the pendulum is plumb, the driven needle should be adjusted to the maximum energy position; when the pendulum is struck by air, the driven needle should be stable without jumping
The ground is brought to zero, and the maximum allowable return to zero difference is ± 0.1% of the maximum energy of the pendulum.
5.2.2 Energy loss includes energy lost from air resistance, bearing friction and pointer friction. Should meet the requirements of Table 2.
Table 2 Requirements on energy loss
Maximum energy per pendulum/J 0.5 1 > 1 ~ ≤10 > 10 ~ ≤60 > 60
Energy loss should not be greater than /% of maximum impact energy 4.0 3.0 2.0 1.0 0.5
5.2.3 The distance from the axis of the pendulum axis to the center of the strike (ll) should be consistent with the distance (l) of the axis of the pendulum axis to the center of the sample.
It should be 0.995l ± 0.005l.
5.2.4 The maximum allowable value of the relative deviation of the pendulum torque from its nominal value is ± 0.5%. Maximum allowable value of fluctuation
0.5%.
5.2.5 The maximum allowable relative error between the initial potential energy Kp of the pendulum and the nominal energy KN is shown in Table 3.
Table 3 Maximum allowable relative error between the initial potential energy Kp of the pendulum and the nominal energy KN
Maximum impact energy per pendulum/J 0.5 1 > 1 ~ ≤10 > 10 ~ ≤60 > 60
Tolerance of initial position /% 4.5 3.5 2.5 ± 1.5 ± 1.0
5.2.6 Accuracy of dial indexing marks. When less than 50% of the nominal energy KN, indicating the energy KS and the initial potential
The maximum allowable value of the relative error of Kp is ± 0.5%; when 50% ~ 80% of the nominal energy, the indicated energy KS and
The maximum allowable relative error of absorbed energy KV is ± 1%.
5.2.7 The impact speed should be 5m/s ~ 5.5m/s, but any value in the range of 3m/s ~ 6m/s is allowed.
Bright.
5.2.8 The angle between the contact line of the impact knife and the horizontal axis of the specimen shall be 90 ° ± 2 °.
5.2.9 The main dimensions of the impact blade should conform to national standards GB/T 229, GB/T 1043, GB/T 3808, etc.
Requirements related to test methods and technical standards (see Appendix C).
5.3 Anvil and support
5.3.1 The two bearing surfaces of the anvil should be parallel, and the difference should not exceed 0.1mm. The plane of the two bearing surfaces of the support
The included angle between the plane and the plane on which the two supporting surfaces of the anvil are located shall be 90 ° ± 0.1 °.
(Please refer to Appendix C and Appendix D for specific size requirements)
5.3.2 The two bearing surfaces of the support shall be parallel and the difference shall not exceed 0.1mm. The support shall be such that the axis of the specimen and the pendulum
The parallelism of the shaft axis is within 3/1000.
5.3.3 There shall be sufficient space to ensure that the sample that has been blown away from the testing machine freely without hindrance and placed in the swing position.
The hammer body does not spring back until the hammer has finished swinging. The width of each part of the pendulum passing between the anvils should not exceed 18mm.
5.4 Indication device
5.4.1 Inspection of analog indicating device
The analog indicating device shall be scaled in angular units or energy units.
The indexing value of the indicating device should not be greater than 1/100 of the nominal value, and at least 0.25% of the reading energy should be estimated.
5.4.2 Inspection of digital indicating device
Digital indicating devices shall be scaled in angular units or energy units.
The minimum resolution of the indicating device of the testing machine can be at least 1/400 of the nominal energy.
5.5 Indirect verification using standard samples
5.5.1 Indirect verification is to check the comprehensive performance of the testing machine using V-notch standard samples. Standard Sample Technique
The requirements shall meet the requirements of GB/T 18658-2002. See Table 4 for the standard deviations allowed for standard impact specimens.
Table 4 Allowed standard deviation of V-notch standard impact test specimens
Energy KR Standard Deviation
< 40J ≤2.0J
≥40J ≤5% KR
The V-notch standard sample size is 55mm × 10mm × 10mm.
The standard energy value of a standard impact specimen shall be within one of the following ranges.
Low energy (L) level. standard energy value < 30J
Medium energy (M) level. 30J≤standard energy value < 110J
High energy (H) level. 110J ≤ standard energy value < 220J
Ultra-high energy (UH) level. standard energy value ≥220J
Note 1. When a V-notch standard impact specimen is not obtained, other shapes of standard impact specimens can be used, such as arc,
For rectangular standard impact samples, see Appendix A. The arbitration test uses a V-notch standard impact specimen.
Note 2. When the result of the indirect test is not satisfactory, the direct test should be performed as the first test.
5.5.2 Use standard samples to monitor the performance of the testing machine throughout its life.
For example. the verification of the testing machine; the periodical inspection of the testing room; the inspection of the testing machine when abnormal test data is found.
5.5.3 When using a V-notch standard sample, the error and repeatability of the indication value of the testing machine shall meet the requirements of Table 5.
Table 5 Maximum allowable values of display error and repeatability
Energy level error repeatability
< 40J ± 4J 6J
≥40J ± 10% KR 15% KR
5.5.4 When using non-V-notch standard sample inspection, the error and repeatability of the indication value of the testing machine should meet the requirements of Table 6.
set.
Table 6 Maximum allowable value of indication error and repeatability
Energy level error repeatability
< 40J ± 2.4J 3.6J
≥40J ± 6% KR 9% KR
6 General technical requirements
6.1 The testing machine should be firmly installed on a stable, vibration-free and solid foundation to ensure that the quality of the foundation is not less than that of the pendulum.
40 times the amount. Base level is 0.5/1000.
6.2 The test machine shall have the name, model, specification, mark, number, date of manufacture, and manufacturer.
6.3 The connection between the pendulum and the hammer body of the testing machine and the hammer body and the impact knife should be firm. The pendulum should be straight, the scale of the dial
The marking shall be clear and free from other defects that affect the test results. The pendulum control mechanism should be flexible, and the locking mechanism should be accessible.
by. The testing machine shall have appropriate protective devices.
7 Control of measuring instruments
Control of measuring instruments includes. first verification, subsequent verification and in-use inspection.
7.1 Verification conditions
7.1.1 The temperature range for normal verification should be 23 ℃ ± 5 ℃, the temperature during verification should be stable, and the temperature change should not exceed
Over 2 ° C.
7.1.2 The test machine shall be in normal working condition during the check.
7.1.3 For verification equipment and measuring instruments, see Table 7.
Table 7 Verification equipment and measuring instruments
Remarks on the verification items of technical characteristics
1 level 0.2 frame, pendulum moment, etc./
2 Optical tilt meter 5 ′ potential energy, tilt angle detection /
3 calipers
Graduation value is not lower than
0.02mm division
Related part size /
Prism, feeler, protractor, half
Caliper, square
Universal measuring tool
Clearance, angle, impact
Blade R, anvil R,
Two sides of the pendulum and the sample
Block verticality
5 Rectangular section sample 10mm × 9.5mm clearance between impact knife and sample /
6 Strike point thrust block
10mm × 20mm ×
100mm steel block, in
100mm long intermediate processing
10mm depth, included angle
30 °, tip R are
2mm and 8mm V-shape
Slot thrust block
Hit the pendulum
Force. The impact blade is
Selection of R2 V-groove
R2 thrust block;
For impact blade R8
Selection of V-groove R8
Force block
Flat on the support
Pendulum knife in the middle
For pushing into the V-groove
502 glue bonding,
At the end of the thrust block
Center (corresponding to pendulum
(Hammer hit point)
7 Dial indicator, magnetic stand, stopwatch
Compliant with General
Gage requirements
Pendulum shaft clearance, strike center /
8 Weighing machine (dynamometer) 0.1 pendulum moment, pendulum shaft clearance with corresponding accessories
9 Pendulum bracket height adjustable support pendulum
Have a certain
load capacity
10 Standard impact test specimen
Energy standard deviation
< 40J ≤2J
≥40J ≤5%
Impact energy
According to the scope of use
Choose energy level
7.2 Verification items
The test items for the first verification, subsequent verification and in-use inspection of the testing machine are shown in Table 8.
Table 8 Verification Items
Serial number verification item The first verification and subsequent verification
1 Appearance
2 Installation status--
3 Base level, support level--
4 Clearance between impact blade and specimen--
5 Pendulum side parallelism, verticality--
6 Center difference between impact knife center and anvil span
7 Axial clearance, radial clearance of the swing shaft-
8 Point return to zero difference, energy loss
9 Strike Center--
10 Initial potential energy of pendulum, indicated energy of dial, impact speed--
Size, assembly, etc. of impact blades, anvils and supports
Claim
12 indicating device--
13 Indirect verification using standard impact specimens
Note. "" in the table indicates the items that should be inspected; "-" indicates that the items can be omitted. The first inspection of the test machine after overhaul of replacement parts
Scheduled.
7.3 Inspection method
7.3.1 First verification of the testing machine
7.3.1.1 Direct verification method
(1) General technical requirements are to pass visual inspection. Check the level of the machine base with a spirit level.
Requirements of Chapter 6.
(2) When the pendulum is freely suspended, a 10 mm × 9.5 mm rectangular cross-section sample is
9.5mm cross-section direction is placed on the support, check the gap between the impact knife edge and the sample.
(3) the parallelism of the side of the pendulum and the swing plane, use a dial indicator to gently hold the side of the pendulum, and the needle can
When measuring by swing, use a string to pull the pendulum lightly to observe the variable of the dial indicator.
Track length calculation. The perpendicularity between the side of the pendulum and the sample support shall be checked with a square, feeler, and quadrant measuring instrument.
(4) The alignment of the center of the pendulum impact knife with the centering template and caliper and the center of the span of the anvil shall be verified.
Record B requirements; then glue the V-notch specimen to carbon paper, align the specimen between the anvil,
Hit the sample, and check the distance from the center line of the impact knife mark on the sample to the top of the V-notch.
(5) Verification of axial and radial clearance of the pendulum shaft.
① Place the thrust point thrust block in the middle of the sample support, so that the impact knife lies close to its V-shaped notch.
Put a few drops of 502 glue on the V-shaped notch to make it stick. (After testing, remove the thrust block and clean all stickies with acetone
(Joint 502 glue residue)
② Place the magnetic meter holder with the dial indicator in the proper position on the mainframe. a) When the dial indicator is vertically aligned with the impact knife
When measuring the blade, it is used to measure the axial clearance of the pendulum shaft; b) When the dial indicator is vertically aligned with the center above the pendulum shaft, measure the pendulum shaft
Radial clearance.
③ Aim the dynamometer at the center of the thrust point to apply force. a) Equivalent to the effective weight W of the pendulum (see Figure E.1)
4% measure the axial clearance of the pendulum shaft; b) apply a force of 150N ± 10N to measure the radial clearance of the pendulum shaft.
Note. For testing machines with a nominal energy of less than 60J, you can take the joint of the pendulum rod and the pendulum shaft with your hand and push it in the direction of the axis of the pendulum shaft.
Pull the pendulum, read the difference between the maximum value and the minimum value of the dial indicator from the end of the pendulum shaft, and only check the axial clearance of the pendulum shaft.
(6) The pendulum is returned to zero by visual inspection.
(7) Verification of energy loss
① Energy loss caused by pointer friction.
Operate the testing machine in a conventional manner, without placing a sample on the support, and record the angle of rise β1 or energy E1 indicated by the pointer. Do not
To adjust the position of the pointer, then raise the pendulum again for the second test, and record the rising angle β2 or energy E2. Pendulum
During the ascent, the energy loss p caused by the friction of the pointer is calculated as follows.
When reading in angle units p = M (cosβ1-cosβ2) (1)
When reading in energy units p = E1-E2 (2)
The values of β1 and β2 or the values of E1 and E2 shall be the average of four measurements.
② Energy loss caused by bearing friction and air resistance in half cycle.
After measuring the values of β1 and β2 or E1 and E2 according to ① above, place the pendulum in the initial position. Do not readjust
Move the needle, release the pendulum without impact and vibration, let it swing for five full cycles, and enter the sixth cycle.
At the beginning of the first half cycle, adjust the slave needle to approximately 5% of the full scale of the dial, and record the values of β3 and E3.
value. The energy loss p ′ caused by bearing friction and air resistance within half a cycle is calculated as follows.
When the dial is reading at an angle, p ′ = 111M
(cosβ3-cosβ2) (3)
When the dial reads in energy units, p ′ = 111
(E3-E2) (4)
Note. In actual tests, when the angle of rise is β, if these energy losses need to be considered, the
The amount of pβ calculated by subtracting the following formula.
pβ = pββ1
p′α βα β2
(5)
Because β1 and β2 are approximately equal to α, in practical applications, the pβ value calculated by the following approximate formula can be subtracted.
pβ = pβα p ′
α β
2α
(6)
For a testing machine scaled in energy units, the β value can be calculated as.
β = arccos [1-1/M (Kp-KV)] (7)
The total energy loss pp ′ caused by friction as measured above shall meet the requirements of Table 2.
For digital display impact testing machine, it does not have the effect of pointer friction.It should ...
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