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Electric and electronic products--Basic environmental test regulations for electricians--Test Ea: The impact method
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Standard ID | GB/T 2423.5-2019 (GB/T2423.5-2019) | Description (Translated English) | Environmental testing - Part 2: Test methods - Test Ea and guidance: Shock | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | K04 | Classification of International Standard | 19.040 | Word Count Estimation | 26,214 | Date of Issue | 2019-05-10 | Date of Implementation | 2019-12-01 | Drafting Organization | The Fifth Electronics Research Institute of the Ministry of Industry and Information Technology, Guangzhou Intelligent Equipment Research Institute Co., Ltd., Shanghai Institute of Quality Supervision and Inspection Technology, Wuhu Saibao Information Industry Technology Research Institute Co., Ltd. | Administrative Organization | National Standardization Technical Committee for Environmental Conditions and Environmental Testing of Electrical and Electronic Products (SAC/TC 8) | Proposing organization | National Standardization Technical Committee for Environmental Conditions and Environmental Testing of Electrical and Electronic Products (SAC/TC 8) | Issuing agency(ies) | State Administration for Market Regulation, China National Standardization Administration | Standard ID | GB/T 2423.5-1995 (GB/T2423.5-1995) | Description (Translated English) | Environmental testing for electric and electronic products - Part 2: Test methods - Test Ea and guidance: Shock | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | K04 | Classification of International Standard | 19.04 | Word Count Estimation | 19,124 | Date of Issue | 1995/8/29 | Date of Implementation | 1996/8/1 | Older Standard (superseded by this standard) | GB 2423.5-1981; GB 2424.3-1981 | Adopted Standard | IEC 60068-2-27-1987, IDT | Drafting Organization | Five of the Ministry of Electronics Industry | Administrative Organization | National Electrical and Electronic Products Environmental conditions and environmental tests for Standardization Technical Committee | Proposing organization | People Republic of China Ministry of Electronics Industry | Issuing agency(ies) | State Bureau of Technical Supervision | Standard ID | GB 2423.5-1981 (GB2423.5-1981) | Description (Translated English) | Electric and electronic products--Basic environmental test regulations for electricians--Test Ea: The impact method | Sector / Industry | National Standard | Classification of Chinese Standard | K04 | Word Count Estimation | 6,675 | Date of Issue | 1981/8/10 | Date of Implementation | 1982/4/1 | Adopted Standard | IEC 68-2-27-1972, MOD |
GB/T 2423.5-2019
Environmental testing--Part 2. Test methods--Test Ea and guidance. Shock
ICS 19.040
K04
National Standards of People's Republic of China
Replaces GB/T 2423.5-1995, GB/T 2423.6-1995
Environmental tests. Part 2. Test methods
Test Ea and guidelines. Impact
(IEC 60068-2-27..2008, Environmental testing-Part 2-27. Tests-
TestEaandguidance. Shock, IDT)
Published on May 10,.2019
2019-12-01 Implementation
State Administration of Market Supervision
Published by China National Standardization Administration
Contents
Foreword I
1 range 1
2 Normative references 1
3 Terms and definitions 2
4 Test equipment description 2
4.1 Feature Requirements 2
4.2 Measurement system 5
4.3 Installation 6
5 Severity 6
6 Pretreatment 7
7 Initial inspection and function test 7
8 Test 7
9 Recovery 8
10 Final inspection 8
11 Information to be given in the relevant regulations 8
12 Information to be given in the test report 8
Appendix A (Normative Appendix) Waveform Selection and Application Guidelines10
Appendix B (Informative) Other characteristics of the impulse response spectrum and pulse waveform 16
Appendix C (Informative) Comparison of Impact Tests 21
References 22
Foreword
GB/T 2423 "Environmental Test Part 2" is divided into several parts according to the test method.
This part is Part 5 of GB/T 2423.
This section is drafted in accordance with the rules given in GB/T 1.1-2009.
This section replaces GB/T 2423.5-1995 "Environmental Tests for Electrical and Electronic Products Part 2. Test Methods Test Ea and Guidelines. Impact
Strike "and GB/T 2423.6-1995" Environmental Tests for Electrical and Electronic Products Part 2. Test Methods Test Eb and Guidelines. Collisions ". Headquarters
The content of GB/T 2423.5-1995 and GB/T 2423.6-1995 is integrated. With GB/T 2423.5-1995, GB/T 2423.6-
Compared with.1995, the main technical changes are as follows.
--- Added the requirement of cut-off frequency when using low-pass filter in 4.2 measurement system;
--- In Chapter 5, the requirement for the number of impacts in each direction has been added;
--- The table in Figure 4 combines the original Figure 4 of GB/T 2423.5-1995 and the table of Figure 2 of GB/T 2423.6-1995;
--- The severity level of Table 1 has increased.
This section uses the translation method equivalent to IEC 60068-2-27..2008 "Environmental Tests Part 2-27. Test Test Ea and Guide
Then. Shock.
The Chinese documents that have a consistent correspondence with the international documents referenced normatively in this section are as follows.
--- GB/T 2421.1-2008 Environmental Test Part 1. Overview and Guidelines (IEC 60068-1. 1988, IDT);
--- GB/T 2423.39-2018 Environmental test Part 2. Test method Test Ee and Guide. Bulk cargo test includes
Bounce (IEC 60068-2-55..2013, IDT);
--- GB/T 4798.1-2005 Environmental conditions for the application of electric and electronic products Part 1 Storage (IEC 60721-3-1..1997,
MOD);
--- GB/T 4798.5-2007 Environmental conditions for the application of electric and electronic products Part 5. Ground vehicle use (IEC 60721-3-
5..1997, MOD).
The following editorial changes have been made in this section.
--- Modified the standard name.
This section is proposed and managed by the National Technical Committee for Environmental Conditions and Environmental Testing of Electrical and Electronic Products (SAC/TC8).
This section was drafted. the Fifth Institute of Electronics of the Ministry of Industry and Information Technology, Guangzhou Intelligent Equipment Research Institute Co., Ltd., Shanghai Quality Supervision
Supervision and Inspection Technology Research Institute, Wuhu Saibao Information Industry Technology Research Institute Co., Ltd.
The main drafters of this section. Cheng Debin, Lu Zhaoming, Xie He, Hou Weiguo.
This section replaces GB/T 2423.5-1995 and GB/T 2423.6-1995.
The previous releases of GB/T 2423.5-1995 are.
--- GB/T 2423.5-1981.
The previous releases of GB/T 2423.6-1995 are.
--- GB/T 2423.6-1981;
--- GB/T 2424.4-1981.
Environmental tests. Part 2. Test methods
Test Ea and guidelines. Impact
1 Scope
This part of GB/T 2423 provides standard procedures for determining the ability of a sample to withstand non-repetitive or repetitive impacts of specified severity.
The purpose of this test is to expose the cumulative damage and degradation caused by mechanical weaknesses and/or performance degradation and impact, and to facilitate
Use these materials in conjunction with relevant specifications to determine whether the sample is acceptable. In some cases, this impact test can also be used to determine
Product structural integrity, or as a means of quality control (see A.2).
This test is mainly for samples without packaging and samples whose packaging can be considered as part of the product under transport conditions. if not
Carry out the test with the packaged item and assign it to the test sample. However, if the item is packaged, treat the product and its packaging as one
Test sample. GB/T 2423.43-2008 introduces the acceptance test of packaging products.
This section is written for pulse waveforms, Appendix A gives guidelines for selecting and using these pulse waveforms, and Appendix B discusses
Characteristics of various waveforms.
If possible, the severity of the test and the shock pulse waveform applied to the sample mimic as much as possible the actual transport or
The effect of the working environment; the purpose of the test is to evaluate the structural integrity and compliance with the design requirements (see A.2 and A.4).
During the test, the sample is always fixed to the impact tester table directly or through a fixture.
Note. This section uses the term "shock testing machine" and does not exclude other methods of generating pulse waveforms.
Where applicable, one of the responsibilities of the Technical Committee is to use basic safety publications in the preparation of publications.
2 Normative references
The following documents are essential for the application of this document. For dated references, only the dated version applies to this article
Pieces. For undated references, the latest version (including all amendments) applies to this document.
GB/T 2423.43-2008 Environmental test for electric and electronic products Part 2. Test methods Vibration, shock and similar dynamics
Installation of test samples (IEC 60068-2-47..2005, IDT)
IEC 60068-1 Environmental Testing Part 1. Overview and Guidelines (Environmental testing-Part 1. General and
guidance)
IEC 60068-2-55 Environmental Tests Part 2-55. Test Ee and Guidelines. Bounce (Environmentaltesting-Part 2-
55. Tests-TestEeandguidance. Bounce)
IEC 60721-3-1 Environmental Classification Conditions Part 3. Environmental Classification Parameters and Their Harshness Section 1. Storage
(Classificationofenvironmentalconditions-Part 3. Classificationofgroupsofenvironmentalparame-
tersandtheirseverities-Section1. Storage)
IEC 60721-3-5 Environmental Classification Conditions Part 3. Environmental Classification Parameters and Their Severity Section 5. Ground Vehicle Use
(Classificationofenvironmentalconditions-Part 3. Classificationofgroupsofenvironmentalparame-
tersandtheirseverities-Section5. Groundvehicleinstalations)
Guide104 Preparation of safety publications, basic safety publications, and series of safety publications (Thepreparationofsafety
publicationsandtheuseofbasicsafetypublicationsandgroupsafetypublications)
3 terms and definitions
The following terms and definitions apply to this document.
Note. Most of the terms used are defined in ISO 2041 [1] 1) or IEC 60068-1. The following additional terms and definitions also apply to this section.
1) Numbers in square brackets refer to references.
3.1
Checkpoint
One of the fixed points, and in any case rigidly connected to the fixed point.
Note 1. The test requirements are guaranteed by several checkpoints.
Note 2. If there are more than 4 fixed points, the relevant specifications should specify 4 representative fixed points for inspection.
Note 3. In special cases, such as for large or complex samples, if the inspection point is not required to be close to the fixed point, it is specified in the relevant specifications.
Note 4. When a large number of small samples are installed on a fixture, or when a small sample has many fixed points, a single checkpoint (i.e., reference point) can be selected.
Export control signals. This signal reflects the characteristics of the fixture, not the sample's fixed point. This is only the lowest total
It is only feasible when the vibration frequency is much higher than the upper limit of the test frequency.
3.2
Fixingpoint
The part where the sample is connected to the fixture or impact test bench is usually the place where the sample is fixed.
Note. If the actual installation structure of the sample is used as a fixture, the fixing point is on the installation structure and not on the sample.
3.3
gn
The standard acceleration produced by the gravity of the earth varies with altitude and geographic latitude.
Note. For ease of use, this section rounds the gn value to an integer value of 10m/s2.
3.4
Repetition rate
Number of impacts per second.
3.5
Shock severity level shockseverity
The severity level of the impact test includes peak acceleration, nominal pulse duration, and number of impacts.
3.6
Velocity change
Absolute value of sudden change in speed due to application of prescribed acceleration.
Note. If the speed change occurs in a time shorter than the basic period of the excitation pulse involved, it is usually considered a sudden change.
4 Test equipment description
4.1 Feature requirements
When the specimen is mounted on the impact test bench with or without a clamp, the impact pulse applied at the inspection point shall be similar to Figures 1 and 2
And one of the acceleration vs. time curves shown by the dashed lines in FIG.
4.1.1 Basic pulse waveform
This section includes three types of waveforms. half-sine wave, post-peak sawtooth wave and trapezoidal wave. The choice of waveform depends on several factors, this section
The priority order of waveform selection is given (see A.3).
The prescribed basic pulse waveform is as follows (see A.3).
--- Half sine wave. half cycle of sine wave, as shown in Figure 1;
--- Back peak sawtooth wave. asymmetric triangle with short fall time, as shown in Figure 2;
--- Trapezoidal wave. Symmetrical trapezoid with short rise and fall times, as shown in Figure 3.
The actual pulse should be within the tolerance indicated by the solid line in the relevant figure.
Note. When it is not possible to obtain pulse waveforms that fall within the specified tolerance range, the relevant specifications should specify another method that can be used (see A.5).
Figure 1.Waveform and tolerance range of a half sine wave
Explanation (applies to Figures 1 to 3).
. Nominal pulse line;
. Tolerance range line;
D. the duration of the nominal pulse;
A. The peak acceleration of the nominal pulse;
T1. The shortest time for pulse monitoring when an impact is generated with a traditional impact test bench;
T2. The shortest time for pulse monitoring when an impact is generated with an electric vibration test bench.
Figure 2 Waveform and tolerance range of the post-peak sawtooth wave
Figure 3 Waveform and tolerance range of trapezoidal wave
4.1.2 Repetition rate
The repetition rate should ensure that the relative motion inside the sample between the two impacts is basically zero, and the acceleration value at the checkpoint should be as shown in Figure 1.
Within the tolerances shown (see A.7).
Note. For the evaluation formula of repetition rate, see A.7.
4.1.3 Tolerance of speed change
For all pulse waveforms, the actual speed change should be within ± 15% of its corresponding nominal pulse value.
When the speed change is determined by the integration of the actual pulse, it should be integrated from 0.4D before the pulse to 0.1D after the pulse, where D is the nominal
The duration of the pulse.
Note. If the speed variation tolerance cannot be obtained due to the lack of an accurate integration device, the relevant specifications should specify another method that can be used (see A.5
And A.6).
4.1.4 Lateral motion
When the method of 4.2 is used, the positive or negative peak acceleration perpendicular to the predetermined impact direction at the check point should not exceed the predetermined square.
Up to 30% of the nominal peak pulse acceleration.
Note. If the error requirements of the lateral movement are not met, the relevant specifications should specify another method that can be used (see A.5).
4.2 Measurement system
The characteristics of the measurement system shall ensure that the tolerances required for the actual pulses in the predetermined direction of the checkpoint are measured in Figures 1, 2 and 3.
Within range. The requirements of Figure 4 apply to the frequency response of a control signal measurement system without a low-pass filter. When a low-pass filter is used, the filter
The cut-off frequency fg (-3dB point) of the wave filter characteristics is not lower than.
fg =
1.5
Where.
fg --- the cut-off frequency of the low-pass filter, the unit is kilohertz (kHz);
D --- pulse duration, unit is millisecond (ms).
Can have an important impact on measurement accuracy.The frequency response of the entire measurement system including the accelerometer should be within the tolerance of Figure 4.
Within (see A.5).
Note. The duration of the impact is equal to or less than 0.5 ms.It is not necessary to have such high frequencies as f3 and f4 in Figure 4.Therefore, relevant specifications should specify
Substitute value.
Pulse duration
ms
Low cut-off frequency
Hz
High cut-off frequency
kHz
Frequency at which the response may rise by 1dB
kHz
f1 f2 f3 f4
0.2, 0.3 20 120 20 40
0.5 10 50 15 30
2,3 2 10 5 10
11 0.5 2 1 2
16,18,30 0.2 1 1 2
Figure 4 Frequency characteristics of the measurement system
4.3 Installation
The sample shall be installed on the table of the impact tester or mounted on the table by a clamp according to IEC 60068-2-47.
5 Severity
Relevant specifications should give both pulse waveform and shock severity levels. The relevant specifications should specify that the shock applies to all three axes.
Positive and negative directions. The effect of gravity should be considered when focusing on the attitude of the test. Unless the actual conditions of use are known or otherwise specified,
Use one of the waveforms given in 4.1.1 and the corresponding severity levels in Table 1. Bold is the preferred combination. The corresponding speed change is also in Table 1.
Given in.
The number of impacts in each direction can be selected from the following values.
3 ± 0
100 ± 5
500 ± 5
1000 ± 10
5000 ± 10
Note. If the severity level here cannot simulate the impact of the known environment on the sample, the relevant specifications can use the standard pulse shown in Figure 1, Figure 2 and Figure 3.
One of the waveforms (see A.4) specifies other suitable test severity levels.
Table 1 Severity level of impact test
Peak acceleration
Pulse duration
Half sine
Δν =
πAD × 10
Back peak jagged
Δν = 0.5AD × 10-3
Trapezoid
Δν = 0.9AD × 10-3
m/s2 gn ms m/sm/sm/s
Note
50 5 6 0.2a 0.2 0.3
50 5 30 1 0.8 1.4
60 6 11 0.4 0.3 0.6 b
100 10 16 1 0.8 1.4
100 10 11 0.7 0.6 1 c
100 10 6 0.4 0.3 0.5
150 15 6 0.6 0.5 0.8 c
150 15 11 1.1 0.8 1.5
200 20 11 1.4 1.1 2 b
250 25 6 1 0.8 1.4 c
300 30 6 1.1 0.9 1.6
300 30 18 3.4 2.7 4.9
400 40 6 1.5 1.2 2.2 c
400 40 11 2.8 2.2 4
500 50 3 1 0.8 1.4
500 50 11 3.5 2.8 5
Table 1 (continued)
Peak acceleration
Pulse duration
Half sine
Δν =
πAD × 10
Back peak jagged
Δν = 0.5AD × 10-3
Trapezoid
Δν = 0.9AD × 10-3
m/s2 gn ms m/sm/sm/s
Note
800 80 6 3.1 2.4 4.3 c
1000 100 2 1.3 1 1.8 c
1000 100 6 3.8 3 5.4
1000 100 11 7 5.5 9.9
2000.200 3 3.8 3 5.4
2000.200 6 7.6 6 10.8
5000 500 1 3.2 2.5 4.5
10000 1000 1 6.4 5 9
15000 1500 0.5 4.8 3.8 6.8
30000 3000 0.2 3.8 3 5.4
30000 3000 0.3 5.7 4.5 8.1
50000 5000 0.3 9.5 7.5 13.5 d
100000 10000 0.2 12.7 10 18 d
a Bold pulse waveforms are preferred.
b RTCADO160E/F recommends. "Functional impact" 6gn, 3 times in each direction; "Crash impact" 20gn, 1 time in each direction.
c Preferred for repeated impacts.
d These shocks may not be fully realized in accordance with the strict requirements of this section.
6 Pretreatment
Relevant specifications can put forward pre-processing requirements.
7 Initial inspection and function test
The appearance, size and function of the sample shall be tested in accordance with the relevant specifications.
8 Test
Shocks shall be applied in each of the three orthogonal axes of the sample a number of times specified in the relevant specification. When multiple identical samples are tested, the
In order to arrange the samples properly, impact in three axes simultaneously (see A.7).
When installing or transporting, the attitude of the sample is known.Since the impact is most sensitive in a certain direction of an axis, the relevant specifications should stipulate that
Number of impacts on this axis, direction and attitude. Otherwise, the test should be performed in both directions of the three axes. For example, usually the largest shock plus
The speed is along the vertical direction. When the attitude during transportation is known, the impact should be in the direction of the vertical axis. When the attitude is unknown, the relevant specifications should stipulate
Number of impacts per axis (see A.7).
Relevant specifications should specify whether the sample works during the test and whether the function is monitored.
9 Recovery
It is sometimes necessary to provide a period of time after the test and before the final test to bring the sample to the same conditions as the initial test, such as temperature.
Relevant specifications should stipulate the conditions for restoration.
10 Final inspection
The samples shall be inspected for appearance, size, function, and other requirements specified in the relevant specifications.
Relevant specifications should give criteria for sample acceptance or rejection.
11 Information to be given in the relevant specifications
When the relevant specification adopts this test, as long as it is applicable, the writer of the specification should provide the following information. Pay special attention to the asterisk (*) mark
Project because this information is required.
Article number
a) Pulse waveform * 4.1.1, A.3
b) Tolerance 4.1.1, A.5
c) Speed change 4.1.3, A.6
d) Lateral motion 4.1.4
e) Excitation axis, test attitude and test axis * Chapter 8
f) Installation method * 4.3
g) Severity rating * Chapter 5, A.4
h) Impact direction and number of impacts * Chapter 5, Chapter 8
i) Preprocessing Chapter 6
j) Chapter 7 of Initial Inspection and Functional Inspection
k) Chapter 7 of Functional Testing
l) Work Mode and Function Monitoring Chapter 8
m) Recover Chapter 9
n) Criteria for acceptance and rejection * Chapter 10
o) Final Inspection Chapter 10
12 Information to be given in the test report
The test report should give at least the following information.
a) the customer (name and address);
b) laboratory (name and address);
c) test report (issue date, unique identification number);
d) test date;
e) test purpose (development test, verification test, etc.);
f) test standard, version (procedures related to the test);
g) sample description (unique identification number, picture, photo, quantity, evaluation of the first inspection of the sample, etc.);
h) installation of samples (fixture characteristics, pictures, photos, excitation axes);
i) excitation axis (test attitude and excitation axis);
j) the performance of the test equipment (transverse motion, etc.);
k) measurement system, sensor location (description, picture, photo, etc.);
l) measurement system uncertainty (calibration data, last date and next date);
m) initial, intermediate or final measurements;
n) demanding severity levels (from test specifications);
o) Test severity and documentation (from checkpoints);
p) Test conclusions (evaluation of sample conditions);
q) test situation records;
r) test summary;
s) the person in charge of the test (name and signature);
t) Send (Report Distribution List).
Note. Test logs should be written in the test records, for example, a chronological list of test runs with test parameters, observations and actions taken during the test,
And measured data sheets. Test logs can be attached to test reports.
Appendix A
(Normative appendix)
Waveform Selection and Application Guidelines
A.1 Introduction
This section provides a test method that reproduces how the sample was affected during transport or use. This test is not a reproduction of reality
surroundings.
In order to enable different people to obtain consistent test results in different laboratories, the parameters specified in this test are
Over-standardized with appropriate tolerances. Standardization of values can also enable components to withstand some of the test rigors specified in this section.
Cool level ability to classify.
A.2 Application scope of the test
Many samples are susceptible to shock during use, storage, handling, and transportation. The magnitude of these shocks varies widely and is complex
Nature.
The impact test provides a simple method for determining the non-repetitive and repetitive impact of a sample. This test is to mount the sample on
The test is performed on the fixture or impact test bench. If the sample is repeatedly impacted in bulk when installed or transported, it should
Test in accordance with IEC 60068-2-55 (see Appendix C).
Impact tests are also applicable to structural integrity tests performed on component samples for identification and/or quality management. In these cases
In general, high-acceleration impacts are usually used.The main purpose is to apply a known impact to the internal structure of the sample (especially the cavity sample).
Strike force (see Chapter 1).
To ensure the integrity of all test information, the author of the specification should refer to Chapter 11 of this section.
A.3 Pulse waveform (see Chapter 1)
According to the purpose of the test, three commonly used "classic" shock pulse waveforms can be used (see 4.1.1 and Table 1).
Semi-sinusoidal pulses are suitable for simulating the impact of a linear system's impact or the deceleration of a linear system, such as the elastic structure.
Hit.
Back peak sawtooth pulses have a more uniform response spectrum than half-sine pulses and back peak saw pulses.
Trapezoidal pulses can produce a higher response over a wider frequency spectrum than half-sine pulses. If the purpose of the experiment is to simulate
This kind of shock waveform can be used for the impact of the impact environment caused by the explosion bolt of the space detector or satellite launch section.
Note. The most commonly used are half-sine pulses, trapezoidal pulses are basically not used for component samples.
See Appendix B for information on the shock response spectrum associated with these pulses.
When the impact response spectrum of the working or transport environment is known, Figure A.1, Figure A.2 and Figure A.3 should be referred to in order to choose the closest to this impact
Pulse waveform of the response spectrum. When the impact response spectrum of the work or transport environment is unknown, Tables A.1 and A.2 should be consulted because they list
Test severity grades and pulse waveforms for samples of all types of transportation and various modes of work.
For packed samples, the characteristics of shocks during loading and unloading and transportation are usually simple, so you can use
A half-sinusoidal waveform pulse obtained by checking the speed variation.
Explanation.
I = initial response spectrum;
R = residual response spectrum.
Figure A.1 Impact response spectrum of a symmetric half-sine pulse
Explanation.
I = initial response spectrum;
R = residual response spectrum.
Figure A.2 Shock response spectrum of a back-to-peak sawtooth pulse
Explanation.
I = initial response spectrum;
R = residual response spectrum.
Figure A.3 Shock response spectrum of a symmetrical trapezoidal pulse
A.4 Test severity level
The test severity levels and pulse waveforms applied to the sample shall be as close as possible to the conditions during which the sample will be transported, stored, handled, or used.
To withstand the environment, if the purpose of the test is to evaluate the integrity of the structure, it should withstand the environment required by the design.
For the same sample, perform a non-repeatable impact test (three impacts in each axis and in each direction).
The ability to withstand the greatest stresses in the life cycle is a common and appropriate way.
Similarly, repeated stress tests with lower stress can determine the ability of the sample to withstand repeated impacts, or determine material fatigue during use due to material fatigue.
Law results.
The transportation environment is usually harsher than the use environment. In this case, the selection of the test severity level needs to be consistent with the transportation environment. Of course
However, although the samples only need to withstand the environmental conditions of transportation, they are usually required to operate in working environmental conditions. So, if possible, samples are usually
Can perform impact tests under the above two conditions, that is, parameter measurement after impact test in transportation environment conditions and test in working environment conditions
Perform an impact test of the functional inspection during the inspection.
Consideration should be given to giving sufficient safety margin between the severity of the test and the actual environmental conditions.
When the actual working or transportation environment is unknown, the appropriate test severity level should be selected from Table 1.
It should be emphasized that the impact test is based on experience and basic sufficient tests to give credible measurements and does not simulate the real environment.
In determining the test severity level, the writer of the specification should consider the relevant content in the series of environmental conditions standards, for example, IEC 60721,
That is, IEC 60721-3-1 and IEC 60721-3-5, but it should be kept in mind that the values listed in these standards are the actual impacts.
Can provide standard impact pulses for testing consistent with impact effects during life.
Table A.1 Typical examples of pulse waveforms and test severity levels for various applications
Severity rating
Acceleration waveform duration
m/s2 gn ......
......
GB/T 2423.5-1995
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
GB/T 2423.5-1995 / IDT IEC 68-2-27:1987
Replacing GB 2423.5-81
GB 2424.3-81
Environmental Testing for Electric and Electronic
Products - Part 2: Test Methods - Test Ea and
Guidance: Shock
APPROVED ON: AUGUST 29, 1995
IMPLEMENTED ON: AUGUST 01, 1996
Approved by: State Bureau of Technical Supervision
Table of Contents
Foreword ... 3
IEC Foreword ... 4
1 Objective ... 5
2 General Description ... 5
3. Definitions ... 6
4. Description of Test Apparatus ... 7
5. Severities ... 8
6 Pre-Conditioning ... 9
7 Initial Inspection ... 9
8 Conditional Test ... 9
9 Recovery ... 10
10 Final Inspection ... 10
11 Information to be Given in the Relevant Specification ... 10
Appendix A (Normative) Guidance ... 14
Appendix B (Normative) Shock Response Spectrum and Other
Characteristics of Pulse Waveform ... 21
Appendix C (Normative) Comparison among Collision Tests ... 31
Foreword
This Standard equivalently adopts the International Electrotechnical Commission
standard 3rd edition (1987) of IEC 68-2-27 “Environmental Testing – Part 2: Test
Methods – Test Ea and Guidance: Shock”.
This Standard replaced GB 2423.5-81 “Electric and Electronic Products - Basic
Environmental Test Regulations for Electricians - Test Ea: The Impact Method” and GB
2424.3-81 “Electric and Electronic Products - Basic Environmental Test Regulations
for Electricians – Guidelines for Impact Tests”.
GB 2423.5-81 and GB 2424.3-81 were drafted by reference of the International
Electrotechnical Commission standard 2rd edition (1972) of IEC 68-2-27 “Basic
Environmental Test Regulations – Part 2: Test Methods – Test Ea and Guidance:
Shock”; divided one standard of the International Electrotechnical Commission into two
standards; its text became the shock test methods in GB 2423.5; while its appendix
became the shock test guidance in GB 2424.3. This revision incorporates the test
methods and guidance; like the 3rd edition of IEC 68-2-27, add Clause 3 Definitions.
Increase the appendix from 1 to 3; namely, Appendix A: Guidance; Appendix B: Shock
Response Spectrum and Other Characteristics of the Pulse Waveform; Appendix C:
Comparison of Shock Test Methods. Relax restrictions for tolerance requirements of
pulse waveforms.
This Standard was first-time published in 1981; first-time revised in August, 1995. It is
implemented since the August 01, 1996.
The original China’s national standards of GB 2423.5-81 and GB 2424.3-81 were
abolished at the same time since the date of implementation.
This Standard’s Appendixes A, B and C are standard ones.
This Standard was proposed by the Ministry of Electronics Industry of the People’s
Republic of China.
This Standard shall be under the jurisdiction of National Technical Committee on
Environmental Conditions of Electric and Electronic Products and Environmental Test
of Standardization of China.
Drafting organization of this Standard: No. 5 Institute of Ministry of Electronics Industry.
Chief drafting staffs of this Standard: Xu Yongmei, and Wang Shurong.
Environmental Testing for Electric and Electronic
Products - Part 2: Test Methods - Test Ea and
Guidance: Shock
1 Objective
To provide a standard procedure for determining the ability of a specimen to withstand
specified severities of bump.
2 General Description
This Standard was drafted according to the pulse waveforms; refer to Appendix A for
guidance on selecting and using these pulse waveforms. The characteristics of various
pulse waveforms shall be discussed in Appendix B. This Standard includes three pulse
waveforms, namely, semi-sine pulse, post-peak zigzag pulse and trapezoidal pulse.
The selection of pulse waveform depends on many factors, and the selection itself is
difficult, therefore, this Standard does not give priority sequence of the waveforms (see
Clause A3).
The purpose of the test is to reveal mechanical weakness and/or performance
degradation; use these materials, and combine with relevant regulations to determine
whether a specimen is acceptable or not. It may also be used, in some cases, to
determine the structural integrity of specimens or as a means of quality control (see
Clause A2).
This test is primarily intended for unpackaged specimens and for items in their
transport case when the latter may be considered as part of the specimen itself.
The bumps are not intended to reproduce those encountered in practice. Wherever
possible, the test severity applied to the specimen and shock pulse waveforms should
be such as to reproduce the effects of the actual transport or operational environment
to which the specimen will be subjected to or to satisfy the design requirements if the
object of the test is to assess structural integrity (see Clauses A2 and A4).
For the purpose of this test the specimen is always fastened to the fixture or the table
of the bump tester during conditioning.
In order to facilitate the use of this Standard, the text of this Standard also listed the
geographical latitude. For the purposes of this Standard, the value of gn, is rounded up
to the integer of 10 m/s2.
4. Description of Test Apparatus
4.1 Characteristic requirements
When the bump tester and/or fixture are loaded with the specimen, the shock pulse
applied at the check point shall be approximate to the one of the nominal curves about
acceleration versus time shown in virtual line.
4.1.1 Basic pulse shape
The true value of the pulse shall be within the tolerance limit in the relevant Figures
shown in solid line.
NOTE - Where it is not practicable to achieve a pulse waveform falling within the specified
tolerance. The relevant specification should state the alternative procedure to be applied (see
Clause A5).
All specified pulse waveforms are as follows, and their order of arrangement does not
indicate that the front pulse is prioritized.
Post-peak zigzag pulse: an asymmetrical triangle with a short fall time, as shown in
Figure1.
Half-sine pulse: half cycle of a sine wave, as shown in Figure 2.
Trapezoidal pulse: a symmetrical quadrilateral with short rise and fall time, as shown
in Figure 3.
4.1.2 Speed variation tolerance
For all pulse waveforms, the actual speed variation shall be within ±15% of its
corresponding nominal pulse value.
When the speed variation is determined by the integral of the actual pulse, it shall be
begun from pre-pulse 0.4D integral to post-pulse 0.1D, where D is the duration of the
nominal pulse.
NOTE: If the speed variation tolerance is not available due to lack of an accurate integration
device, the relevant specification should state the alternative procedure to be applied.
4.1.3 Transverse motion
The positive or negative peak acceleration at the check point, perpendicular to the
intended bump direction, shall not exceed 30% of the value of the peak acceleration
of the nominal pulse in the intended direction, when determined with a measuring
system in accordance with Sub-clause 4.2 (see Clause A5).
NOTE – If the transverse motion tolerance cannot be achieved, the relevant specification
should state the alternative procedure to be adopted (see Clause A5).
4.2 Measuring system
The frequency characteristics of the measuring system shall be such that it can be
determined that the true value of the actual pulse as measured in the intended direction
at the check point is within the tolerance range in the Figure prescribed by Sub-clause
4.1.1.
The frequency characteristics of the overall measuring system, which includes the
accelerometer, can have a significant effect on the measuring accuracy and shall be
within the tolerance limits shown in Figure 4 (see Clause A5).
4.3 Mounting
During the conditional test, the specimen shall be mounted to the fixture or the table of
the bump tester by its normal mounting means. Mounting method shall be as specified
in GB/T 2423.43-1995 Environmental Testing for Electric and Electronic Products -
Part 2: Test Methods - Mounting Requirements and Guidance of Components,
Equipment and Other Products for Shock (Ea), Collision (Eb), Vibration (Fc and Fd),
Stable Acceleration (Ga) and Similar Dynamic Tests.
5. Severities
The relevant specification shall give both the pulse waveform and the test severity level.
A pulse waveform given in 4.1.1 and a severity level specified in Table 1 shall be
selected.
Unless otherwise specified, a set of data on the same line in Table 1 shall be used.
The data of each line with * shall be preferred. The specified corresponding speed
variation is listed in Table 1 (see Clause A4).
NOTE: If the severity level in the Table 1 can’t simulate the effect of a known environment on
the sample, the relevant specification can use one of three standard pulse waveforms shown
in Figure 1, Figure 2 and Figure 3 (see Clause A4) to specify other suitable test severity level.
The relevant specifications state:
a) Whether the specimen is to be operated during the shock test and whether it is
to be monitored for its function; and/or
b) The specimen shall be able to subjected to the applied shock.
For both cases, the relevant specification shall give criteria for receipt or rejection.
9 Recovery
The relevant specification can propose recovery requirements.
10 Final Inspection
The specimen shall be submitted to the appearance, dimensional and functional
checks prescribed by the relevant specification.
The relevant specification shall give the criteria for receipt or rejection.
11 Information to be Given in the Relevant Specification
When relevant specification adopts this test, it shall give the following information:
a) Pulse waveforms (A3) (4.1.1);
b) Tolerance under special conditions (A5) (4.1.1);
c) Speed variation under special conditions (A6) (4.1.2);
d) Transvers motion under special conditions (4.1.3);
e) Mounting mode (4.3);
f) Severity level (A4) (Clause 5);
g) Pre-conditioning (Clause 6);
h) Initial inspection (Clause 7);
i) The direction and number of shocks only under special conditions (A7) (8.1);
j) Operating mode and functional monitoring (8.2);
Appendix A
(Normative)
Guidance
A1 Introduction
The test provides a method by which effects on a specimen comparable with those
likely to be experienced in practice in the environment to which the specimen will be
subjected during either transportation or operation can be reproduced in the test
laboratory. The basic intention of the test is not to simulate the real environment.
The parameters given are standardized and suitable tolerances are chosen in order to
obtain similar results when a test is carried out at different locations by different people.
The standardization of values also enables components to be grouped into categories
corresponding to their ability to withstand certain severities given in this Standard.
In order to facilitate the use of this Appendix the related clause numbers of the text are
referred to herein.
A2 Applicability range of shock test
Many specimens are susceptible to shock during use, loading/unloading,
transportation processes. The magnitude of these shock varies widely and has
complex properties. This Test provides a very convenient method for determining the
ability of a sample to withstand these non-repetitive shock conditions. For the repetitive
shock, it shall use GB/T 2423.6-1995 Environmental Testing for Electric and Electronic
Products - Part 2: Test Methods-Test Eb and Guidance: Bump (Appendix C).
The shock test is also applicable to structural integrity tests performed on the
component specimens for identification or quality management. In these cases, high
accelerations hocks are usually applied, the main purpose is to apply a known shock
to the internal structure of the specimen (especially for the specimens with cavities)
(Clause 2).
The specification writer intending to adopt this test should refer to Clause 11
“Information to be given in the relevant specification” in order to ensure that all such
information is so provided.
A3 Pulse waveform (Clause 2)
This Standard specifies three commonly used shock pulse waveforms. Any one of
them can be selected according to the purpose of the test (see also 4.1.1 and Table 1
of this Standard).
A5 Tolerance
The test method described in this standard is capable of a high degree of
reproducibility when the tolerance requirements relating to the pulse waveform,
velocity variation, and transverse motion are complied with.
However, there are certain exceptions to these tolerance requirements and these are
primarily applicable to specimens which provide a highly reactive load, that is with
mass and dynamic responses which would influence the characteristics of the bump
tester. In these cases, it is expected that the relevant specification will specify relaxed
tolerances or state that the values obtained will be recorded in the test report (see Sub-
clauses 4.1. 1, 4.1.2 and 4.1.3).
When testing highly reactive specimens it may be necessary to carry out preliminary
bump conditioning to check the characteristics of the loaded bump tester. With complex
specimens, where only one or a limited number is provided for test, the repeated
application of bumps prior to the definitive test, particularly for the lower number of
bumps, could result in an over-test and possibly unrepresentative cumulative damage.
In such instances it is recommended that, whenever possible, the preliminary checking
should be carried out using a representative specimen (such as rejected equipment),
or, when this is not available, it may be necessary to use model having the correct
mass and center of gravity position to carry out shock pre-conditioning. However, it
needs to be noted that the above model is unlikely to have the same dynamic response
as the real specimen.
For the frequency response of the entire measurement system including the
accelerometer, it is an important factor to reach the required pulse waveform and
severity level, which shall be within the tolerance range shown in Figure 4. If a low-
pass filter is used to reduce the high-frequency resonance effects inherent in the
accelerometer, then the amplitude-frequency characteristics and phase-frequency
characteristics of the measurement system must be considered to avoid the distortion
in the measurement system itself (see 4.2).
For the shock with pulse duration equal to or less than 0.5ms, the f3 and f4 shown in
Figure 4 may be too high; in this case, the relevant specification may be specified
otherwise (see 4.2).
A6 Speed variation (see 4.1.2)
For all pulse waveforms, it is necessary to determine the actual velocity variation. This
can be done in a number of ways., amongst which are:
- the shock pulses not involving rebound motion, which shall be determined by the
collision speed.
- the free-fall testers shall be determined by the height of falling and rebounding.
Appendix B
(Normative)
Shock Response Spectrum and Other Characteristics of Pulse
Waveform
Introduction
In order to utilize the improved technology in the shock test and to further develop the
impact tester, Test Ea requires one of three pulse waveforms with a specified severity
level to be applied to the fixed point of the specimen without limiting the used shock
tester. The selection of the pulse waveforms and severity levels shall be based on the
technical consideration applicable to the design and type of the specimen.
From the point of view for specifying the reproducibility of the test conditions and
reproducibility of influence on the actual shock environmental conditions, all methods
are feasible. In order to make the test both reproducible and practical, some basic
concepts must be considered when developing the test procedures and described as
follows:
B1 Concept of shock response spectrum
When developing the shock test procedures, the acceleration shock response
spectrum of various pulse waveforms has been considered; because under many
important practical situations, they provide useful magnitudes for potential damage to
the shock. However, it must be acknowledged that, from certain aspects, their
application has limitations.
The acceleration shock response spectrum can be considered to be the maximum
acceleration response as a function of the resonant frequency of the system for a given
undamped mass-elastic system under specified shock excitation. In most cases, the
maximum acceleration of the vibrations systems determines the maximum mechanical
stress of the joint and the maximum relative displacement of the elastic member.
Let the frame shown in Figure B1 withstand a shock excitation with a specified pulse
waveform, namely, the time period of the acceleration is d2Xf/dt2 = a(t). Since the mass,
m, determines the resonant frequencies (f1, f2, f3, etc.), the system response is an
oscillation with different acceleration time period.
Figure B2a is an example of pulse waveform with a peak acceleration of A and a
duration of D; its response acceleration d2X1/dt2 = a(t), etc. can refer to Figure B2b.
The shock response spectrum (see Figure B2c) is caused by an infinite number of
given in this Appendix has two coordinates, namely, amax/A as fD function, and amax as
f function shall be the special case of pulse duration and peak acceleration.
B2 Application of Level-I shock response spectrum in actual conditions
In components and equipment, their internal components typically form a more
complex system than an undamped system. For instance, the damped series multi-
degree-of-freedom system shown in Figure B3. In this case, when the external system
excites the oscillation due to the shock, the internal system may be damaged due to
the coupling resonance effect. Such effect can be illustrated by a series of effective
high-order shock spectra that give the mass-elastic separation system combined
resonant frequency.
If the resonant frequencies of the series system can be completely separated, then the
Level-I shock spectrum can give a reasonable magnitude of the potential damage
caused by comparing different pulse waveforms.
If the resonance is excited during the pulse period, then various masses in the system
shall reach the highest acceleration. In this case, the oscillation acceleration overlaps
with the pulse itself. Therefore, when suing a pulse with a short rise time, it is obvious
form Claus B3 that the damage is mostly likely to occur.
Generally, the damping can reduce the response of the mid-frequency-band during the
pulse duration and reduce the response of the mid-and-high-frequency-band after the
pulse. Meanwhile, damping can also reduce the amplitude of the oscillation and the
duration of oscillation; thus, attenuate the response of the internal system. So the
damage from the damping system may be lower than from the undamped system,
especially for the multi-degree-of-freedom system. Therefore, the shock response
spectrum of the undamped system represents the worst possible damage.
It can be seen from the above that the acceleration shock spectrum can’t fully explain
the damage capability of the shock. Nevertheless, this simplified method of expression
is sufficient to select a suitable shock pulse for the actual structure.
Before comparing the shock spectrum, the accurate shock test shall compare the long-
term response oscillation exhibited by the residual shock spectrum with the importance
of the short response oscillation exhibited by the initial response spectrum, and make
a judgment. Such judgment shall be based on a possible failure mode.
B3 Shock response spectrum of nominal pulse waveform
The acceleration shock response spectrum of the nominal pulse waveforms
recommended in this Standard can refer to Figures B4, B5 and B6.
Due to use of a dimensionless scale, for the same pulse waveform, regardless of its
pulse duration, it has the same form of shock spectrum. The normalized frequency
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