GB/T 4857.23-2021 Packaging—Basic tests for transport packages—Part 23：Vertical random vibration test method
Packaging - Basic tests for transport packages - Part 23: Vertical random vibration test method
1 Scope
This document specifies the principle, equipment, test procedure and test report of vertical random vibration test on transport packages.
This document is applicable to the vertical random vibration test on transport packages or unit loads. It provides methods for assessing the performance of a package in terms of its strength or the protection that it offers to its contents when it is subjected to vertical vibration. The test discussed in this document can be performed either as a single test, or as a part of a sequence of tests.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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.
GB/T 4122.5 Packaging terms - Part 5: Inspection and test
GB/T 4857.1 Packaging - Basic tests for transport packages - Part 1: Identification of parts when testing (GB/T 4857.1-2019, ISO 2206: 1987, MOD)
GB/T 4857.2 Packaging - Basic tests for transport packages - Part 2: Temperature and humidity conditioning (GB/T 4857.2-2005, ISO 2233: 2000, MOD)
GB/T 4857.3 Packaging - Basic tests for transport packages - Part 3: Stacking test methods using a static load (GB/T 4857.3-2008, ISO 2234: 2000, IDT)
GB/T 4857.17-2017 Packaging - Basic tests for transport packages - Part 17: General rules for the compilation of performance test (ISO 4180: 2009, MOD)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 4122.5 and the following apply.
3.1
power spectral density, PSD
square mean value of acceleration signal of random vibration at unit frequency
3.2
acceleration mean square root value
square root value of PSD integral in all frequency ranges
4 Principle
Under the specified environmental conditions, the test specimen is placed on a vibration table according to the predetermined direction and fixing mode and subjected to the vertical random vibration test with the predetermined test level for a certain duration with certain frequency range. The temperature and humidity conditions, test duration, power spectral density, attitude of the test specimen and method of restraint are predetermined.
5 Test equipment
5.1 Vibration table
The vibration table shall have sufficient size, strength, stiffness and bearing capacity. This structure shall be able to ensure that the vibration table is kept horizontal when vibrating, and its lowest resonant frequency is higher than the highest test frequency. The vibration frequency shall meet the requirements of the frequency range required by the test, with a resolution of at least 1Hz.
The vibration table may be equipped with the following auxiliary devices:
a) low fences restricting sideways and endways movements during testing;
b) high fences or other means of maintaining a superimposed load in position on the test specimen during testing;
c) devices for simulating the fixing of packages during transport.
Furthermore, the apparatus shall meet the requirements of Clause 6.
5.2 Vibration measurement and control system
A system comprising accelerometers, signal conditioners and a computer, capable of:
a) generating random vibration with the required power according to the set PSD;
b) controlling the motion of the vibration table by feeding back the signal from the accelerometer which monitors the table acceleration;
c) performing the analysis with at least 120 statistical degrees of freedom; and
d) having a test system response accurate to 5% over the frequency range specified for the test.
6 Test procedure
6.1 Test specimen preparation
Foreword i
Introduction vi
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Test equipment
5.1 Vibration table
5.2 Vibration measurement and control system
6 Test procedure
6.1 Test specimen preparation
6.2 Numbering of each part of the test specimen
6.3 Test specimen conditioning
6.4 Temperature and humidity conditions during the test
6.5 Test steps
7 Test report
Annex A (Informative) Power spectral density curve and data of random vibration in generic transportation
Annex B (Informative) Power spectral density curve and data of random vibration actually collected
Annex C (Informative) Power spectral density curve and data used in international related random vibration test
Annex D (Informative) Power spectral density curve and data of random vibration in China road transportation and Beijing-Shanghai railway transportation
Bibliography
