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Standard ID | GB/T 2423.56-2023 (GB/T2423.56-2023) | Description (Translated English) | Environmental testing - Part 2: Test methods - Test Fh: Vibration, broadband random and guidance | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | K04 | Classification of International Standard | 19.040 | Word Count Estimation | 36,318 | Date of Issue | 2023-09-07 | Date of Implementation | 2024-04-01 | Older Standard (superseded by this standard) | GB/T 2423.56-2018 | Drafting Organization | Guangzhou University, the Fifth Institute of Electronics of the Ministry of Industry and Information Technology, Beijing University of Aeronautics and Astronautics, Shanghai Institute of Quality Supervision and Inspection Technology, Suzhou Suzhou Testing Group Co., Ltd., Beijing Zhongyuan Environmental Testing Mechanical and Electrical Equipment Technology Co., Ltd., China Aviation Comprehensive Technology Research Institute, Guangdong Laibotong Testing Equipment Co., Ltd., Guangzhou Saibao Tengrui Information Technology Co., Ltd., Suzhou Xinke Testing Technology Co., Ltd. | Administrative Organization | National Standardization Technical Committee on Environmental Conditions and Environmental Testing of Electrical and Electronic Products (SAC/TC 8) | Proposing organization | National Standardization Technical Committee on Environmental Conditions and Environmental Testing of Electrical and Electronic Products (SAC/TC 8) | Issuing agency(ies) | State Administration for Market Regulation, National Standardization Administration | Standard ID | GB/T 2423.56-2018 (GB/T2423.56-2018) | Description (Translated English) | Environmental testing -- Part 2: Test methods -- Test Fh: Vibration, broadband random and guidance | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | K04 | Classification of International Standard | 19.020 | Word Count Estimation | 29,216 | Date of Issue | 2018-12-28 | Date of Implementation | 2019-07-01 | Older Standard (superseded by this standard) | GB/T 2423.56-2006 | Quoted Standard | GB/T 2423.43-2008; GB/T 2424.26-2008; IEC 60050-300; IEC 60068-1; IEC 60068-2-6; IEC 60068-5-2; IEC 60721-3-0; IEC 60721-3-1; IEC 60721-3-2; IEC 60721-3-3; IEC 60721-3-4; IEC 60721-3-5; IEC 60721-3-6; IEC 60721-3-7; IEC 60721-3-9; IEC GUIDE 104; ISO 2041 | Adopted Standard | IEC 60068-2-64-2008, IDT | Drafting Organization | GuangZhou University | Administrative Organization | National Technical Committee for Environmental Conditions and Environmental Testing Standardization of Electrical and Electronic Products | Regulation (derived from) | National Standard Announcement No. 17 of 2018 | Proposing organization | National Technical Committee for Environmental Conditions and Environmental Testing Standardization of Electrical and Electronic Products (SAC/TC 8) | Issuing agency(ies) | State Administration of Markets and China National Standardization Administration | Summary | This standard specifies the test method for random vibration standards to determine the ability of a sample to withstand dynamic loads without the occurrence of unacceptable functional degradation and/or compliance with the overall structure under the specified random vibration test. Wideband random vibrations can be used to identify stress accumulation effects and degradation of specific functions. This information, combined with relevant specifications, can be used to assess whether a sample is acceptable. This standard applies to samples that may be subject to random vibrations in a transport or work environment, such as in aircraft, spaceships, and land vehicles. It is primarily used for unpackaged samples and as part of the sample itself during transport. sample. However, for a packaged sample, the sample, along with its packaging, is considered a sample. For packed samples | Standard ID | GB/T 2423.56-2006 (GB/T2423.56-2006) | Description (Translated English) | Environmental testing for electric and electronic products. Part 2: Test methods. Test Fh: Vibration, broad-band random (digital control) and guidance | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | K04 | Classification of International Standard | 19.020 | Word Count Estimation | 30,379 | Date of Issue | 2006-11-08 | Date of Implementation | 2007-04-01 | Quoted Standard | GB/T 2298-1991; GB/T 2421-1999; GB/T 2423.10-1995; GB/T 2423.43-1995; GB/T 4796; IEC 60050-301-1983; IEC 60050-302-1983; IEC 60050-303-1983; IEC 60068; IEC 60068-2 | Adopted Standard | IEC 60068-2-64-1993, IDT | Drafting Organization | Guangzhou University | Administrative Organization | National Electrical and Electronic Products Environmental Standardization Technical Committee | Regulation (derived from) | China Announcement of Newly Approved National Standards No. 11 of 2006 (No. 98 overall) | Proposing organization | China Electrotechnical Society | Issuing agency(ies) | Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China; Standardization Administration of China | Summary | This standard provides two standard test method (Method 1 and Method 2) to determine the test sample subjected to a specified band random vibration. Can not be considered an experimental approach than other more severe test method, the main difference is the Test Method 2 provides additional information to quantify the test applied, it has a better reproducibility. This standard also reveals random vibration caused by the cumulative effects of stress and specific mechanical performance, and the use of such information and related specifications to assess the acceptability of the test sample. Sometimes, this standard is also used to demonstrate the adaptability of mechanical environmental samples and/or study their dynamics. This standard applies to the transport or work environment may be subject to random vibration of the sample, as in aircraft, spacecraft and land transport modes, it is mainly used without packaging samples, as well as its packaging during transport as part of test sample itself sample. This standard applies to electrical and electronic products, but is not limited to this, also applicable to other areas of the product. |
GB/T 2423.56-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 19.040
CCS K 04
GB/T 2423.56-2023 / IEC 60068-2-64:2019
Replacing GB/T 2423.56-2018
Environmental testing - Part 2: Test methods - Test Fh:
Vibration, broadband random and guidance
(IEC 60068-2-64:2019, Environmental testing - Part 2-64: Tests - Test Fh: Vibration,
broadband random and guidance, IDT)
ISSUED ON: SEPTEMBER 07, 2023
IMPLEMENTED ON: APRIL 01, 2024
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 4
Introduction ... 6
1 Scope ... 7
2 Normative references ... 7
3 Terms and definitions ... 9
4 Requirements for test apparatus ... 17
4.1 General ... 17
4.2 Basic motion ... 18
4.3 Cross-axis motion ... 18
4.4 Mounting ... 19
4.5 Measuring systems ... 19
4.6 Vibration tolerances ... 20
4.7 Control strategy ... 23
4.8 Vibration response investigation ... 24
5 Severities ... 24
5.1 Test frequency range ... 25
5.2 RMS value of acceleration ... 25
5.3 Shape of acceleration spectral density curve ... 25
5.4 Test duration ... 26
6 Preconditioning ... 26
7 Initial measurements and functional performance test ... 26
8 Testing ... 26
8.1 General ... 26
8.2 Initial vibration response investigation ... 27
8.3 Low-level excitation for equalization prior to testing ... 28
8.4 Random testing ... 29
8.5 Final vibration response investigation ... 30
9 Recovery ... 30
10 Final measurements and functional performance ... 30
11 Information to be given in the relevant specification ... 30
12 Information to be given in the test report ... 32
Annex A (Informative) Standardized test spectra ... 34
A.1 Transportation ... 34
A.2 Stationary installation ... 35
A.3 Equipment in wheeled vehicles ... 36
A.4 Equipment installed in airplanes and helicopters ... 38
Annex B (Informative) Guidance ... 40
B.1 General introduction ... 40
B.2 Requirements for testing ... 41
B.3 Testing procedures ... 43
B.4 Equipment normally used with vibration isolators ... 43
B.5 Test severities ... 44
B.6 Equipment performance ... 44
B.7 Initial and final measurements ... 44
Annex C (Informative) Guidance on non-Gaussian distribution/high kurtosis tests .. 45
C.1 Non-Gaussian random vibration ... 45
C.2 Methods to generate non-Gaussian random vibration ... 45
C.3 Additional analysis ... 48
C.4 Frequency range ... 49
Annex NA (Informative) Constituent documents of GB/T 2423 ... 50
Bibliography ... 54
Foreword
This document is drafted in accordance with the rules provided in GB/T 1.1-2020
Directives for standardization - Part 1: Rules for the structure and drafting of
standardizing documents.
This document is part 56 of GB/T 2423. See Annex NA for the published parts of GB/T
2423.
This document replaces GB/T 2423.56-2018 Environmental testing - Part 2: Test
methods - Test Fh: Vibration, broadband random and guidance. Compared with GB/T
2423.56-2018, except for structural adjustments and editorial changes, the main
technical changes are as follows:
a) Add the term “kurtosis” (see 3.39);
b) Add the term “skewness” (see 3.40);
c) Add the term “beta distribution” and “Figure 4” (see 3.41);
d) Add relevant provisions for “parameters determined during non-Gaussian vibration
testing” (see Clause 5);
e) Add “For non-Gaussian vibration testing, the time history shall be recorded and the
kurtosis, skewness (if applicable) and amplitude probability density shall be
established as required by the relevant specification” and “Figure 5” (see 8.4.1).
This document is identical to IEC 60068-2-64:2019 Environmental testing - Part 2-64:
Test - Test Fh: Vibration, broadband random and guidance.
This document makes the following minimal editorial changes:
a) In order to coordinate with the existing standards, change the standard name to
Environmental testing - Part 2: Test methods - Test Fh: Vibration, broadband
random and guidance;
b) Add Annex NA.
Please note that some of the contents of this document may involve patents. The issuing
organization of this document is not responsible for identifying patents.
This document was proposed and managed by the National Technical Committee on
Environmental Conditions of Electric and Electronic Products and Environmental Test
of Standardization Administration of China (SAC/TC 8).
Drafting organizations of this document: Guangzhou University, The Fifth Institute of
Electronics, Ministry of Industry and Information Technology, Beijing University of
Environmental testing – Part 2: Test methods – Test Fh:
Vibration, broadband random and guidance
1 Scope
This document demonstrates the adequacy of specimens to resist dynamic loads without
unacceptable degradation of its functional and/or structural integrity when subjected to
the specified random vibration test requirements.
Broadband random vibration may be used to identify accumulated stress effects and the
resulting mechanical weakness and degradation in the specified performance. This
information, in conjunction with the relevant specification, may be used to assess the
acceptability of specimens.
This document is applicable to specimens which may be subjected to vibration of a
stochastic nature resulting from transportation or operational environments, for
example in aircraft, space vehicles and land vehicles. It is primarily intended for
unpackaged specimens, and for items in their transportation container when the latter
may be considered as part of the specimen itself. However, if the item is packaged, then
the item itself is referred to as a product and the item and its packaging together are
referred to as a test specimen. This standard may be used in conjunction with GB/T
2423.43-2008, for testing packaged products.
If the specimens are subjected to vibration of a combination of random and
deterministic nature resulting from transportation or real-life environments, for
example in aircraft, space vehicles and for items in their transportation container, testing
with pure random may not be sufficient. See GB/T 2424.26-2008 for estimating the
dynamic vibration environment of the specimen and based on that, selecting the
appropriate test method.
Although primarily intended for electrotechnical specimens, this standard is not
restricted to them and may be used in other fields where desired (see Annex A).
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 2041, Vibration and shock – Vocabulary
specimen. It is therefore recommended that prior to mounting a specimen in its fixture
a dynamic response survey or modal test be performed on the fixture and necessary
modifications performed to avoid putting unrealistic loads into the specimen.
B.2 Requirements for testing
B.2.1 Single-point and multipoint control
The test requirements are confirmed by the acceleration spectral density computed from
the random signal measured at the reference point.
For stiff or small-size specimens, for example in component testing, or if it is known
that the dynamic influence of the specimen is low and the test fixture is stiff in the test
frequency range there need only be one checkpoint, which then becomes the reference
point.
In the case of large or complex specimens, for example equipment with well-spaced
fixing points, either one of the checkpoints, or some other point is specified for
reference. For a fictitious point, the acceleration spectral density is computed from the
random signals measured at the checkpoints. It is recommended that for large and/or
complex specimens a fictitious point is used.
B.2.1.1 Single-point control
Measurements are made at one reference point and the indicated acceleration spectral
density is directly compared with the specified acceleration spectral density.
B.2.1.2 Multipoint control
When multipoint control is specified or necessary, two frequency domain control
strategies are available.
B.2.1.2.1 Averaging strategy
In this method the acceleration spectral density is computed from the signal of each
checkpoint. A composite acceleration spectral density is found by arithmetically
averaging the acceleration spectral density of these checkpoints.
The arithmetically averaged acceleration spectral density is then compared to the
specified acceleration spectral density.
B.2.1.2.2 Extremal strategy
In this method, a composite acceleration spectral density is computed from the
maximum or the minimum extreme value of each frequency line of the acceleration
spectral density measured at each checkpoint. This method is also called ‘maximum’ or
‘minimum’ strategy, because it produces an acceleration spectral density which
represents the envelope of the acceleration spectral densities of each checkpoint.
......
GB/T 2423.56-2018
Environmental testing--Part 2. Test methods--Test Fh. Vibration, broadband random and guidance
ICS 19.020
K04
National Standards of People's Republic of China
Replaces GB/T 2423.56-2006
2018-12-28 release
2019-07-01 Implementation
State Administration of Market Supervision
Published by China National Standardization Administration
Contents
Foreword I
Introduction III
1 range 1
2 Normative references 1
3 Terms and definitions 2
4 Test requirements 6
4.1 General requirements 6
4.2 Basic movements 6
4.3 Lateral motion 6
4.4 Installation 6
4.5 Measurement system 6
4.6 Vibration tolerance 7
4.7 Control 9
4.8 Vibration response check 10
5 Severity Level 10
5.1 Test frequency range 10
5.2 Root mean square value of acceleration 10
5.3 Spectral Patterns of Acceleration Spectral Density 10
5.4 Test duration 11
6 Pretreatment 11
7 Initial test and function test 11
8 Test 11
8.1 General requirements 11
8.2 Initial vibration response check 11
8.3 Low magnitude incentive equilibrium before the test 12
8.4 Randomized trials 12
8.5 Final Vibration Response Check 12
9 Recovery 13
10 Final test and function test 13
11 Information to be given in the relevant specifications 13
12 Information to be given in the test report 14
Appendix A (informative) Standard test spectrum 15
Appendix B (informative) Guideline 21
References 24
Foreword
GB/T 2423 "Environmental Test Part 2" is divided into several parts according to the test method.
This part is the 56th part 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 2423.56-2006 "Environmental Tests for Electrical and Electronic Products-Part 2. Test Methods Test Fh. Broadband
Random Vibration (Digital Control) and Guidelines. Compared with GB/T 2423.56-2006, in addition to editorial changes, the main technical changes are as follows.
--- Removed the bandwidth symbol "Br" (see 3.1 of the.2006 version);
--- Added "lateral motion", "actual motion", "fixed point", "control method", "single point control", "measurement point", "sampling frequency", and "multipoint control"
Terms and definitions for "control strategy", "peak factor", and "test frequency range" (see 3.1, 3.2, 3.3, 3.4, 3.4.1, 3.6, 3.12, 3.13,
3.16, 3.37);
--- Modified "multi-point average control" to "multi-point control" and the definition of terms (see 3.4.2, 3.20 of the.2006 version);
--- Added the acceleration spectrum density symbol "ASD" (see 3.18);
--- The definition of the term "controlling the acceleration spectral density" has added "or virtual reference points" (see 3.19, 3.5 of the.2006 version);
--- Modified the terminology of "Clip of the drive signal", "Effective frequency range", "Indication of acceleration spectral density", "Root mean square value" and "Standard deviation"
Meaning (see 3.21, 3.22, 3.27, 3.33, 3.34, 3.10, 3.11, 3.17, 3.28, 3.29 of the.2006 edition);
--- Increased the frequency resolution symbol "Be" (see 3.26);
--- Added the statistical DOF symbol "DOF" (see 3.36, 3.31 of the.2006 version);
--- Modify the term "random wave" in the definition of "true acceleration spectral density" to "random signal" (see 3.38,.2006 version
3.33);
--- Deleted the definitions of the terms "deviation", "damping ratio", "distortion", "frequency sweep cycle" and "window function" (see 3.3, 3.8,
3.9, 3.32, 3.34);
--- Amended the relevant content of "General requirements" (see 4.1, 4.1 of the.2006 version);
--- Amended the relevant content in the "Basic Movement" and added notes (see 4.2, 4.3.1 of the.2006 version);
--- Increased the "measurement system" (see 4.5);
--- Increased "control" (see 4.7);
--- Related relevant content in "Vibration Response Check" (see 4.8, 4.2 of.2006 edition);
--- Added the rule "Test samples should be installed in accordance with the requirements of IEC 60068-2-47. In all cases, in IEC 60068-2-47
To select a curve, first square it and then multiply it by the acceleration spectral density (ASD) or directly by the sine amplitude. "(See 4.4,.2006 edition
4.4);
--- Added the stipulation that "the probability density function for calculating the reference point at the beginning, middle and end of the test should last 2 minutes each. Related regulations
Fan should specify the tolerance of the normal distribution "and" Figure 2 "(see 4.6.2, 4.3.3 of the.2006 edition);
--- Added the title "ASD and rms values" (see 4.6.1, 4.3.4 of the.2006 version);
--- Added the rule "If the relevant regulations provide that the confidence level is to be met in the test, Figure 3 should be used to calculate the accuracy of the statistical results
Sex "(see 4.6.3, 4.3.5 of the.2006 edition);
--- Modified the method and formula for selecting the frequency resolution Be and related content (see 4.6.4, 4.3.6 of the.2006 version);
--- Modified "Acceleration Spectrum Density" to "Acceleration Root Mean Square" (see 5.2, 5.3 of the.2006 edition);
--- Modified the "initial test" to "initial test and function test" (see Chapter 7, Chapter 7 of the.2006 edition);
--- Modified "Vibration response" to "Initial vibration response" and related content (see 8.2,.2006 version 8.2);
--- Modified the "random vibration test" to "random test" and related content (see 8.4,.2006 version 8.4);
--- Modified the "test duration" (see 5.4, 5.5 of the.2006 version);
--- Modified the "intermediate detection" to "intermediate detection and function detection" and related content (see 8.4.2, 8.5 of the.2006 version);
--- Modified the "final test" to "final test and function test" and related content (see Chapter 10, Chapter 10 of the.2006 edition
chapter);
--- Added "Information to be given in the test report" (see Chapter 12);
--- Removed the normative appendix "Vibration Response Check" (see Appendix A of the.2006 edition);
--- Informative appendix "Standard Test Spectrum" (see Appendix A).
This section uses the translation method equivalent to IEC 60068-2-64..2008 "Environmental Tests Part 2-64. Test Test Fh. Broadband
Random Vibrations and Guidelines.
The Chinese documents that have a consistent correspondence with the international documents referenced normatively in this section are as follows.
--- GB/T 2298-2010 Vocabulary for mechanical vibration, shock and condition monitoring (ISO 2041..2009, IDT);
--- GB/T 2421.1-2008 Overview and guidelines for environmental testing of electric and electronic products (IEC 60068-1. 1988, IDT);
--- GB/T 2422-2012 Environmental Test Test Method Compilation Guide Terms and Definitions (IEC 60068-5-2..1990,
IDT);
--- GB/T 2423.10-2008 Environmental testing for electric and electronic products Part 2. Test methods Test Fc. Vibration (sine)
(IEC 60068-2-6..1995, IDT);
--- GB/T 16499-2017 Number of electrical and electronic safety publications and basic safety publications and multi-professional shared safety publications
Application guidelines (IEC Guide104..2010, NEQ).
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. Guangzhou University, the Fifth Institute of Electronics of the Ministry of Industry and Information Technology, Beijing University of Aeronautics and Astronautics, Shanghai Quality Supervision
Inspection Technology Research Institute, Suzhou Sutest Test Instrument Co., Ltd., Beijing Zhongyuan Environmental Test Electromechanical Equipment Technology Co., Ltd., China Aviation Comprehensive
Institute of Technology.
The main drafters of this section. Xu Zhonggen, Ji Chunyang, Li Chuanri, Lu Zhaoming, Xu Liyi, Zhang Yue, Xu Ming, and Liu Qihua.
The previous versions of the standards replaced by this section are.
--- GB/T 2423.56-2006.
introduction
The broadband random vibration test of this part of GB/T 2423 is applicable to components, equipment and other products that will be subjected to random vibration during their lifetime.
The product is called "test sample" in the following text. This test method is based on digitally controlled random vibration test technology. Relevant specifications such as
As required, this section allows appropriate adjustments to the test method to apply to test samples of other types of products.
Compared with most other experiments, the test Fh is not based on deterministic techniques but based on statistical techniques. Broadband Random Vibration
Tests are described in terms of probability and statistical averages.
It should be noted that random vibration tests always require a certain degree of engineering judgment, and both the supply and demand sides must fully realize this fact. Have
The author of the relevant specification needs to choose the test method and the severity level suitable for the test sample and its application.
This test method is mainly based on the use of an electric or a servo-hydraulic shaker with a computer-aided control system.
Appendices A and B are informative appendixes that give examples of test spectra for tests under different conditions, detailed rules to be considered when preparing specifications,
Guidelines.
Environmental tests. Part 2. Test methods
Test Fh. Broadband Random Vibration and Guidelines
1 Scope
This part of GB/T 2423 provides the standard test method for random vibration to determine whether the sample is subjected to the specified random vibration test.
The ability to resist dynamic loads without unacceptable functional degradation and/or compliance with the overall structure.
Broadband random vibration can be used to identify cumulative effects of stress and degradation of specific functions. Combining this information with relevant specifications, you can
Used to assess whether the sample is acceptable.
This section applies to samples that may be subjected to random vibrations in the transport or work environment, such as in aircraft, spacecraft and land vehicles
It is mainly used for samples without packaging, and samples whose packaging is part of the sample itself during transportation. However, for already
For packaged samples, the samples together with their packaging are regarded as samples. For the test of packed samples, this section can be compared with GB/T 2423.43-
Commonly used in.2008.
If the sample is subjected to random and deterministic mixed vibration during transportation or actual life cycle environment, such as in aircraft, spacecraft and container transportation
In losing, it is not enough to test the sample with purely random conditions. Refer to GB/T 2424.26-2008 to estimate the sample dynamic vibration ring
Environment, and select the appropriate test method based on this.
This section mainly applies to electrical and electronic products, but also applies to products in other fields (see Appendix A).
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)
GB/T 2424.26-2008 Environmental testing for electric and electronic products. Part 3. Supporting documents and guidelines for vibration test selection
(IEC 60068-3-8..2003, IDT)
IEC 60050-300 International Electrotechnical Terminology (IEV) Electronic measurement and electronic measuring instruments-Part 311. General principles of measurement
Part 312. General principles of electronic measurement. Part 313. Classification of electronic measuring instruments. Part 314. Technical terms related to the type of instrument.
IEC 60068-1 Environmental Testing Part 1. Overview and Guidelines (Environmental testing-Part 1. General and guidance)
IEC 60068-2-6 Environmental Tests Part 2-6. Test Methods Test Fc. Vibration (Sine) (Environmental testing-Part 2-6. Tests-TestFc. Vibration (sinusoidal)]
IEC 60068-5-2 Environmental Tests Part 5-2. Guidelines for the Preparation of Test Methods Terms and Definition
IEC 60721-3 (all parts) Classification of environmental conditions Part 3. Classification of environmental parameter groups and their severity
Preparation of IEC Guide104 safety publications and application guidelines for basic safety publications and multi-professional shared safety publications
ISO 2041 Vibration and Shock-Vocabulary
3 terms and definitions
The following terms and definitions apply to this document.
Note. The terms used are generally defined in IEC 60050-300, IEC 60068-1, IEC 60068-2-6, IEC 60068-5-2 and ISO 2041. If this
Including the definition of one of these sources will indicate the derivation process and point out deviations from the definitions in these sources.
3.1
Cross-axismotion
The movement along the non-excitation direction is generally performed along two axes orthogonal to the excitation direction.
Note. The lateral movement needs to be measured near the fixed point.
3.2
Actualmotion
The movement represented by the wideband signal returned by the reference point sensor.
3.3
Fixingpoint
The part of the test sample that is in contact with the fixture or shaker is usually the place where the test sample is fixed in use.
Note. If a part of the actual mounting structure is used as a fixture, the fixed point refers to the fixed point of the mounting structure and not the fixed point of the test sample.
3.4
Controlmethods
3.4.1
Single point control
A control method implemented by using a signal from a sensor at a reference point to keep the signal at a prescribed vibration level.
3.4.2
Multipoint control
The method is controlled by sensor signals from various inspection points.
Note. Whether the signal is processed by continuous arithmetic averaging or comparison technology is determined according to relevant specifications. See 3.13.
3.5
gn
The standard acceleration due to the gravity of the earth varies with altitude and geographic latitude.
Note. For ease of use, gn is rounded to 10m/s2 in this section.
3.6
Measuring points
Certain points of data collected during the experiment.
Note. These points are divided into three categories, see 3.7 ~ 3.9 for specific definitions.
3.7
Check-point
The point on the fixture, vibration table or test sample, as close as possible to the fixed point of the test sample, and in any case
Fixed point rigid connection.
Note 1. The use of multiple checkpoints is a measure to ensure that the test requirements are met.
Note 2. If there are less than or equal to four fixed points, all are used as checkpoints. For packaged products, the fixed point at this time is the packing table that the shaker contacts.
On the other hand, if there is no resonance effect of the shaking table or mounting structure in the frequency range of the test, a checkpoint can be used. Otherwise need to use multiple points
Control, but also refer to Note 3. If there are more than four fixed points, the relevant specifications need to specify 4 representative fixed points for inspection.
Note 3. In special cases, such as for large or complex test samples, if the inspection point is not required to be close to the fixed point, it shall be specified in the relevant specifications.
Note 4. When a large number of small test samples are installed on a fixture, or when a small test sample has many fixed points, a single checkpoint (i.e.
(Reference point) to derive the control signal. This signal reflects the characteristics of the fixture, not the fixed point of the test sample. This only works if the fixture is fitted with a test sample
It is only feasible if the lowest resonance frequency after the load is much higher than the upper limit of the test frequency.
3.8
Reference point (single-point control)
The signal selected from the check points is used for test control to meet the requirements of this section.
3.9
Fictitiousreferencepoint (multipointcontrol)
Points derived from multiple inspection points, either manually or automatically, are used for test control to meet the requirements of this section.
3.10
Responsepoints
Points located at specific locations on the test sample. Data are obtained from these points for vibration response analysis.
Note. These points are different from checkpoints or datum points.
3.11
Priority test axes preferredtestingaxes
According to the actual situation, the three orthogonal axes corresponding to the weakest test samples are selected.
3.12
Sampling frequency
The number of discrete amplitudes collected per second for digitally recording or representing a time course.
3.13
Multipointcontrolstrategies
The method of calculating the reference control signal when using multi-point control.
Note. For discussion of control methods in different frequency regions, see 4.7.1.
3.14
Average averaging
The process of determining the control of the acceleration spectral density formed by arithmetically averaging the acceleration spectral densities on the spectral lines corresponding to multiple checkpoints.
3.15
Extreme (maximum or minimum) extremal (maximum or minimum)
Determine the control acceleration spectral density formed by the maximum or minimum value of the acceleration spectral density on the corresponding spectral lines of multiple checkpoints
process.
3.16
Crestfactor
The ratio of the peak value to the root mean square value of the time history.
[ISO 2041]
3.17
-3dB bandwidth-3dBbandwidth
The frequency width between two points corresponding to 0.707 times the maximum response of a single resonance peak in the frequency response function.
3.18
Acceleration spectral density acceleration spectrum density; ASD
When the bandwidth approaches zero and the averaging time approaches infinity, the addition of the central frequency narrowband filter on each unit bandwidth
Mean squared speed signal.
3.19
Control acceleration spectral density
Acceleration spectral density measured at a fiducial or virtual fiducial.
3.20
Control system loop
This includes the following operations.
--- Digitization of analog random signals on reference points or virtual reference points;
--- Perform necessary data processing;
--- Generate an updated analog drive signal for the vibration system power amplifier (see B.1).
3.21
Clipping of drive signals
The limit of the maximum drive signal is expressed by a crest factor (see Figure 1).
3.22
Effective frequency range
Frequency range from 0.5 times f1 to 2.0 times f2 (see Figure 1).
Note. Because of the initial slope and falling slope, the effective frequency range is greater than the test frequency range between f1 and f2.
3.23
Acceleration spectrum density erroraccelerationspectraldensity
The difference between the specified acceleration spectral density value and the control-implemented acceleration spectral density value.
3.24
Equalization
The process of minimizing the acceleration spectral density error.
3.25
Final slope
The part of the acceleration spectral density greater than f2 (see Figure 1).
3.26
Frequency resolution
Be
The width of the frequency interval in the acceleration spectral density, in hertz.
Note. In order to calculate the specified acceleration spectral density in digital analysis, the sampling record is divided into several parts, and the reciprocal of the sampling length (T) of each part is
Resolution. In the frequency range, the number of frequency lines is equal to the number of frequency intervals.
3.27
Acceleration spectrum density indicated acceleration spectral density
The true acceleration spectral density read from the analyzer is affected by instrument error, random error, and system deviation.
3.28
Initial slope
The portion of the acceleration spectral density that is less than f1 (see Figure 1).
3.29
Instrument error
Errors caused by each analog link of the control system and its inputs.
3.30
Random error
Due to the limitation of different actual averaging time and filter bandwidth, the acceleration spectral density estimation error.
3.31
Record
A collection of equally spaced data points in the time domain for fast Fourier transform calculations.
3.32
Reproducibility
The degree of consistency between the results of the same parameter and value measurement under the following different conditions.
--- Different test methods;
--- different measuring instruments;
--- different observers;
--- different laboratories;
--- After a longer time interval relative to the duration of a single measurement;
--- Different instrument usage habits.
Note. The term "reproducibility" can also be applied when some of the above conditions are met.
[IEC 60050-300, amendment]
3.33
Root-mean-squarevalue
The root mean square values of all frequencies of the single-valued function in the interval f1 and f2 are the average of the squared average of the function values in the interval
Square root value (see Figure 2).
3.34
Standard deviation
According to the vibration theory, when the average value of the vibration amplitude is equal to 0, for a random time history, the standard deviation of the vibration is equal to the root mean square value (see
figure 2).
3.35
Statistical accuracy
The ratio of the true value of acceleration spectral density to the displayed value of acceleration spectral density.
3.36
Statistical degrees of freedom
DOF
When using the time averaging method to estimate the acceleration spectral density of random data, the statistical degree of freedom depends on the frequency resolution and the effective average time.
(See Figure 3).
3.37
Test frequency range
In the frequency range between f1 and f2 (see Figure 1), the relevant specifications need to specify that the ASD is a flat spectrum or other spectral shape.
3.38
True acceleration spectral density true acceleration spectral density
Acceleration spectral density of a random signal acting on a test sample.
4 Test requirements
4.1 General requirements
When testing, the entire vibration system including power amplifiers, vibration generators, test fixtures, test samples, and control systems should be full.
Meet the necessary performance requirements.
The standard test method generally consists of the following test sequences, which are applied to the mutually perpendicular axial directions in the test sample.
1) Check the initial vibration response with a low magnitude sine or random excitation (see 8.2);
2) Mechanical load or stress test with random excitation;
3) The final response check is compared with the results of the initial response check.
Mechanical failure (see 8.2 and 8.5).
When the dynamic response is known and irrelevant, or when sufficient data can be collected in the case of full-scale tests, the relevant regulations provide that
No vibration response check is required before and after the test.
4.2 Basic movement
Relevant specifications shall specify the basic movement of the fixed points of the test sample. These fixed points should have approximately the same operation in phase and amplitude.
It should move linearly with respect to the direction of excitation. If it is difficult to achieve exactly the same motion at each point, multi-point control should be used.
Note. For large structures and high frequency ranges, such as 20Hz ~.2000Hz, the dynamic characteristics of test samples may require multi-point control.
4.3 Lateral motion
If required by the relevant specifications, the lateral motion shall be checked by applying sinusoidal or random vibrations as specified in the relevant specifications before the test, or
During the test, additional monitoring channels of two orthogonal axes were used to check the lateral movement.
When the acceleration spectral density of each frequency point of the checkpoint is measured on two axes that are perpendicular to each other, it should not exceed 500Hz.
The specified value should not exceed -3dB of the specified value when it is below 500Hz. Root mean square value of total acceleration of any axis perpendicular to the specified axis
It should not exceed 50% of the root mean square value of the specified axis. For example, in the case of small test samples, the relevant specifications can limit the acceleration of lateral movement
Degree of spectral density to ensure that it does not exceed -3dB of basic motion.
At some frequencies or for test samples with large sizes or high centroids, achieving these values may be difficult. Again, in this case
It is also difficult to achieve these values when the relevant regulations specify a strict level with a large dynamic range. In this case, the relevant specifications
Provision should be made for one of the following.
a) Any lateral movement exceeding the above-mentioned values shall be recorded in the test report;
b) Transverse movements known not to cause damage to the test specimen need not be monitored.
4.4 Installation
The test samples shall be installed in accordance with the requirements of IEC 60068-2-47. In all cases, first select the curve when selecting the curve in IEC 60068-2-47
Multiply the square by the acceleration spectral density (ASD) or directly by the sine amplitude.
4.5 Measurement system
The characteristics of the measurement system shall be such that the actual value of the measured vibration from a given axial point in the reference point is within the tolerance required by the test.
The entire measurement system includes sensors, signal conditioners, data collectors and data processors, and its frequency response has a significant effect on measurement accuracy.
influences. The frequency range of the measurement system should extend from 0.5 times the lowest frequency (f1) of the test to 2.0 times the highest frequency (f2) (see Figure 1).
The frequency response of the measurement system in this frequency range should be flat and within ± 5%. Any further deviations outside this range should be
Recorded in the report.
Figure 1 Tolerance range, initial slope and final slope of acceleration spectral density (see B.2.3)
4.6 Vibration tolerance
4.6.1 ASD and rms values
The indicated values of the specified acceleration spectral density including the instrument error and random error at the reference point in the specified direction are shown in f1 and f2 in Figure 1.
Within ± 3dB tolerance range.
Within f1 and f2, the calculated root mean square value of acceleration must not deviate from the root mean square value of the specified acceleration spectral density by 10%
the above. This value applies to datum points and virtual datum points.
At some frequencies or for test samples with large sizes or high centroids, it may be difficult to achieve these values. In these cases, relevant
The specification should specify a wider tolerance.
The initial and final slopes should be no less than 6dB/oct and no more than -24dB/oct, respectively (see also B.2.3).
4.6.2 Distribution
As shown in Figure 2, the instantaneous acceleration value of the reference point should be approximately normal (Gaussian) distribution. If there is an explicit requirement,
Verification shall be performed (see B.2.2).
The clipping value of the drive signal should be at least 2.5 (see 3.16). Detect the crest factor of the acceleration waveform at the reference point to ensure that the signal contains the
Set a peak value of at least 3 times the rms value, unless otherwise specified by the relevant specifications.
If virtual reference point control is used, the required crest factor is applicable to all checkpoints that form acceleration spectral density control.
The probability density functions used to calculate the reference points at the beginning, middle, and end of the test should each last 2 min. Relevant specifications should provide for normal analysis
The tolerance of the cloth (see Figure 2).
Figure 2 Time history of random excitation;
Gaussian (normal) distribution probability density function
(Crest factor = 3 as an example, see 3.14 and 4.6.2)
4.6.3 Statistical accuracy
Statistical accuracy is determined by statistical degrees of freedom Nd and confidence values (see Figure 3). The statistical degrees of freedom are given by.
Nd = 2Be × Ta (1)
Where.
Be --- frequency resolution;
Ta --- effective average time;
Nd --- Unless otherwise specified in the relevant specifications, Nd should not be less than 120DOF statistical degrees of freedom. If the relevant regulations stipulate that
To meet the confidence level, Figure 3 should be used to calculate the accuracy of the statistical results.
Figure 3 Relationship between statistical accuracy of acceleration spectral density and degrees of freedom at different...
......
GB/T 2423.56-2006
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 19.020
K 04
GB/T 2423.56-2006/IEC 60068-2-64.1993
Environmental Testing for Electric and Electronic
Products - Part 2. Test Methods - Test Fh. Vibration,
Broad-Band Random (Digital Control) and Guidance
(IEC 60068-2-64.1993, IDT)
ISSUED ON. NOVEMBER 08, 2006
IMPLEMENTED ON. APRIL 01, 2007
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of PRC.
Table of Contents
Foreword ... 4
Introduction ... 5
1 Scope ... 6
2 Normative References ... 6
3 Definitions ... 7
4 Requirements for Testing... 12
5 Severities ... 16
6 Pre-conditioning ... 17
7 Initial Measurements ... 18
8 Testing ... 18
9 Recovery ... 20
10 Final Measurements ... 20
11 Information to be Given In the Relevant Specification ... 21
Appendix A (Normative) Vibration Response Investigation ... 28
Appendix B (Informative) Guidance ... 32
Appendix C (Informative) Conversion between Percentage Values and dB .. 45
Figure 1 – Tolerance Band for Distribution of Instantaneous Acceleration
Values ... 22
Figure 2 – Tolerance Boundaries for Acceleration Spectral Density ... 22
Figure 3 – Gaussian (Normal) Probability Density Function ... 23
Figure 4 – Representation of Signal Clipping ... 23
Figure 5 – Non-Gaussian Probability Density Function after Clipping ... 24
Figure 6 – Statistical Accuracy of Acceleration Spectral Density versus
Degrees of Freedom for Different Confidence Levels ... 24
Figure 7 – Relationship between Acceleration Spectral Density and
Frequency ... 25
Figure 8 – Flow Chart for Vibration, Broad-Band Random Test ... 26
Figure 9 – Generalized Transmissibility Factors for Isolators ... 27
Foreword
GB/T 2423 Environmental Testing for Electric and Electronic Products – Part 2. Test
Methods can be divided into multiple parts according to the test methods.
This Part belongs to Part 56 of GB/T 2423 serial standard.
This Part equivalently adopted IEC 60068-2-64.1993 Environmental Testing for
Electric and Electronic Products – Part 2. Test Methods – Test Fh. Vibration, Broad-
Band Random (Digital Control) and Guidance (English Version); however, the following
editorial modifications were made as per the 4.2b) and 5.2 of GB/T 20000.2-2001
Guides for Standardization – Part 2. Adoption for International Standards.
a) Change “This Part of IEC 60086” into “this Part of GB/T 2423” or “this Part”;
b) Use “decimal point” to replace “comma” acting as the decimal point;
c) Delete the foreword of the international standard;
d) To be consistent with other parts of GB/T 2423, change the name of this Part as
the current name.
Appendix A of this Part is normative; while Appendixes B, C are informative.
This Part was proposed by China Electrical Association.
This Part shall be under the jurisdiction of National Technical Committee for
Standardization of Environment for Electric and Electronic Products (SAC/TC 8).
Drafting organizations of this Part. Guangzhou University, The Fifth Electronics
Research Institute of The Ministry of Industry and Information Technology, Shanghai
Electronic Instrument Standard Measurement Testing Institute, Beihang University,
No.301 Institute of Aviation Industry Corporation of China, Beijing Haidian Zhongyuan
Micro Instrument Company, and Suzhou Experiment Instrument Factory.
Chief drafting staffs of this Part. Xu Zhonggen, Ji Chunyang, Lu Zhaoming, Wang
Deyan, Xu Ming, Xu Liyi, Zhang Yue, Ren Min, Yang Zequn, and Du Xueying.
Environmental Testing for Electric and Electronic
Products - Part 2. Test Methods - Test Fh. Vibration,
Broad-Band Random (Digital Control) and Guidance
1 Scope
This Part provides two standard test methods (method 1 and method 2) for determining
the ability of a specimen to withstand specified severities of broad-band random
vibration. Neither test method can be considered more severe than the other, the
difference being primarily that method 2 provides more information to quantify the
applied test, and is therefore more reproducible.
It is also to reveal the accumulated effects of stress induced by random vibration, and
the resulting mechanical weakness and degradation in specified performance and to
use this information, in conjunction with the relevant specification, to assess the
acceptability of specimens. In some cases. this Part may also be used to demonstrate
the mechanical robustness of specimens and/or to study their dynamic behavior...
This Part is applicable to specimens which may be subjected to vibration of a random
nature resulting from transportation or operational environments, for example in aircraft,
space vehicles and land vehicles. It is primarily intended for unpackaged specimens.
and for items in their transportation container when the latter may be considered as
part of the specimen itself.
Although primarily intended for electrotechnical products, this Part is not restricted to
them and may be used in other fields where desired.
2 Normative References
The provisions in following documents become the provisions of this Part through
reference in this Part. For dated references, the subsequent amendments (excluding
corrigendum) or revisions do not apply to this Part, however, parties who reach an
agreement based on this Part are encouraged to study if the latest versions of these
documents are applicable. For undated references, the latest edition of the referenced
document applies.
GB/T 2298-1991 Mechanical Vibration and Shock – Terminology (idt ISO
2041.1990)
GB/T 2421-1999 Environmental Testing for Electric and Electronic Products - Part
1. General and Guidance (idt IEC 60068-1.1988)
GB/T 2423.10-1995 Environmental Testing for Electric and Electronic Products -
Part 2. Test Methods Test Fc and Guidance. Vibration (Sinusoidal) (idt IEC 60068-
2-6.1982)
GB/T 2423.43-1995 Environmental Testing – Part 2. Mounting of Components,
Equipment and Other Articles for Dynamic Tests including Shock (Ea), Bump (Eb),
Vibration (Fc and Fd) and Steady-State Acceleration (Ga) and Guidance (idt IEC
60068-2-47.1982)
GB/T 4796 Classification of Environmental Parameters and their Severities of
Electric and Electronic Products (GB/T 4796-2001, idt IEC 600721-1.1991)
IEC 60050-301.1983 International Electrotechnical Vocabulary (IEV) Chapter 301.
General Terms on Measurements in Electricity
IEC 60050-302.1983 International Electrotechnical Vocabulary (IEV) Chapter 302.
Electrical Measuring Instruments
IEC 60050-303.1983 International Electrotechnical Vocabulary (IEV) Chapter 303.
Electronic Measuring Instruments (Advanced Edition)
IEC 60068 Environmental Testing
IEC 60068-2 Environmental Testing – Part 2. Tests
3 Definitions
The terms used are generally defined in GB/T 2298-1991 or IEC 60050 (301, 302,
303).1983 and in GB/T 2421-1999 or GB/T 2423.10-1995. Where, for the convenience
of the reader, a definition from one of those sources is included here, the derivation is
indicated and departures from the definitions in those sources are also indicated.
The additional terms and definitions that follow are also applicable for the purposes of
this Part.
3.1 -3dB bandwidth (Br)
Frequency bandwidth between two points in a frequency response function which is
0.707 of the maximum response when associated with a single resonance peak (see
4.3.6.2).
[GB/T 2298-1991, modification]
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