ASTM D4728-17(2022)
(Test Method)Standard Test Method for Random Vibration Testing of Shipping Containers
Standard Test Method for Random Vibration Testing of Shipping Containers
SIGNIFICANCE AND USE
4.1 Shipping containers are exposed to complex dynamic stresses in the distribution environment. Approximating the actual damage, or lack of damage, experienced in real life may require subjecting the container and its contents to random vibration tests. In this way, many product and container resonances are simultaneously excited.
4.2 Resonance buildups during random vibration tests are less intense than during sinusoidal resonance dwell or sweep tests. Therefore, unrealistic fatigue damage due to resonance buildup is minimized.
4.3 Random vibration tests should be based on representative field data. When possible, confidence levels may be improved by comparing laboratory test results with actual field shipment effects. Refer to Practice D4169 for recommended random vibration tests. (See Appendix X1 and Appendix X2 for related information.)
4.4 There is no direct equivalence between random vibration tests and sinusoidal vibration tests. Equivalent tests between sine and random, in a general sense, are difficult to establish due to nonlinearities, damping and product response characteristics.
4.5 Vibration exposure affects the shipping container, its interior packing, means of closure, and contents. This test allows analysis of the interaction between these components. Design modification to one or all of these components may be used to achieve optimum performance in the shipping environment.
4.6 Random vibration tests may be simultaneously performed with transient or periodic data to simulate known stresses of this type, that is, rail joints, pot holes, etc.
4.7 Random vibration may be conducted in any axis (vertical or horizontal) or in any package orientation. However, different test levels may be utilized for each axis depending on the field environment that is to be simulated.
SCOPE
1.1 This test method covers the random vibration testing of filled shipping units. Such tests may be used to assess the performance of a container with its interior packing and means of closure in terms of its ruggedness and the protection that it provides the contents when subjected to random vibration inputs.
1.2 This test method provides guidance in the development and use of vibration data in the testing of shipping containers.
Note 1: Sources of supplementary information are listed in the Reference section (1-11).2
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific safety hazard statements are given in Section 6.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4728 − 17 (Reapproved 2022)
Standard Test Method for
Random Vibration Testing of Shipping Containers
This standard is issued under the fixed designation D4728; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D7386Practice for Performance Testing of Packages for
Single Parcel Delivery Systems
1.1 This test method covers the random vibration testing of
2.2 ISO Standards:
filled shipping units. Such tests may be used to assess the
ISO 13355Packaging—Complete, filled transport packages
performanceofacontainerwithitsinteriorpackingandmeans
and unit loads—Vertical random vibration test
of closure in terms of its ruggedness and the protection that it
provides the contents when subjected to random vibration 2.3 ISTA Standards:
ISTA Procedure 1GPackaged-Products 150 lb (68 kg) or
inputs.
Less (Random Vibration)
1.2 This test method provides guidance in the development
ISTA Procedure 3APackaged-Products for Parcel Delivery
and use of vibration data in the testing of shipping containers.
System Shipment 70 kg (150 lb) or Less
NOTE 1—Sources of supplementary information are listed in the
ISTA Procedure 3HProducts or Packaged-Products in Me-
Reference section (1-11).
chanically Handled Bulk Transport Containers
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety, health, and environmental practices and deter-
3.1.1 General—Definitions for the packaging and distribu-
mine the applicability of regulatory limitations prior to use.
tion environments are found in Terminology D996.
Specific safety hazard statements are given in Section 6.
3.2 Definitions of Terms Specific to This Standard:
1.4 This international standard was developed in accor-
3.2.1 bandwidth—the difference, in Hz, between the upper
dance with internationally recognized principles on standard-
and lower limits of a frequency band. For the purposes of this
ization established in the Decision on Principles for the
test method, the bandwidth may be considered equivalent to
Development of International Standards, Guides and Recom-
the frequency resolution of a spectrum analysis.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 3.2.2 closed-loop—a condition of control where the input
may be modified over time by the effect of the output or
2. Referenced Documents
response of the system.
2.1 ASTM Standards:
3.2.3 decibel (dB)—ten times the base 10 logarithm of a
D996Terminology of Packaging and Distribution Environ-
ratio of two power like quantities that is, a PSD. Two PSD
ments
levels that have a ratio of 2.0 differ by 3 dB. Two PSD levels
D4169Practice for Performance Testing of Shipping Con-
that have a ratio of 0.5 differ by −3 dB.
tainers and Systems
3.2.4 equalization—adjustment or correction of the ampli-
D4332Practice for Conditioning Containers, Packages, or
tudecharacteristicsofanelectroniccontrolsignalthroughouta
Packaging Components for Testing
desired frequency range to maintain a desired vibration output
spectrum and level.
This test method is under the jurisdiction of ASTM Committee D10 on
3.2.5 equalizer—instrumentation used to conduct equaliza-
Packaging and is the direct responsibility of Subcommittee D10.21 on Shipping
tion.
Containers and Systems - Application of Performance Test Methods.
Current edition approved May 1, 2022. Published May 2022. Originally
3.2.6 mean-square—the time average of the square of a
published as D-10 Proposal P186. Last previous edition approved in 2017 as
function.
D4728– 17. DOI: 10.1520/D4728-17R22.
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
this test method.
3 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from International Organization for Standardization (ISO), 1, ch. de
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http://www.iso.org.
Standards volume information, refer to the standard’s Document Summary page on Available from International Safe Transit Association (ISTA), 1400 Abbot
the ASTM website. Road, Suite 160, East Lansing, MI 48823-1900, http://www.ista.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4728 − 17 (2022)
3.2.7 overall g rms—thesquarerootoftheintegralofpower 4.2 Resonance buildups during random vibration tests are
spectral density over the total frequency range. less intense than during sinusoidal resonance dwell or sweep
tests. Therefore, unrealistic fatigue damage due to resonance
3.2.8 periodic vibration—an oscillation whose waveform
buildup is minimized.
repeats at equal increments of time.
4.3 Random vibration tests should be based on representa-
3.2.9 power spectral density (PSD)—an expression of ran-
tive field data. When possible, confidence levels may be
dom vibration in terms of mean-square acceleration per unit of
2 2 improvedbycomparinglaboratorytestresultswithactualfield
frequency. The units are g /Hz (g /cycles/s). Power spectral
shipment effects. Refer to Practice D4169 for recommended
density is the limit of the mean square amplitude in a given
random vibration tests. (See Appendix X1 and Appendix X2
rectangular band divided by the bandwidth, as the bandwidth
for related information.)
approaches zero.
4.4 There is no direct equivalence between random vibra-
3.2.10 random vibration—an oscillation whose instanta-
tion tests and sinusoidal vibration tests. Equivalent tests
neousamplitudeisnotprescribedforanygiveninstantintime.
between sine and random, in a general sense, are difficult to
The instantaneous amplitudes of a random vibration are
establish due to nonlinearities, damping and product response
prescribedbyaprobabilitydistributionfunction,theintegralof
characteristics.
which over a given amplitude range will give the probable
4.5 Vibration exposure affects the shipping container, its
percentage of time that the amplitude will fall within that
interior packing, means of closure, and contents. This test
range.Randomvibrationcontainsnoperiodicorquasi-periodic
allows analysis of the interaction between these components.
constituent. If random vibration has instantaneous magnitudes
Design modification to one or all of these components may be
that occur according to the Gaussian distribution, it is called
usedtoachieveoptimumperformanceintheshippingenviron-
“Gaussian random vibration.” Gaussian random vibration has
the property that the rms level is equal to the standard ment.
deviation, or 1 sigma, and that the amplitude will fall within 3
4.6 Random vibration tests may be simultaneously per-
sigma, or 3 times the rms level, 99.7% of the time.
formed with transient or periodic data to simulate known
stresses of this type, that is, rail joints, pot holes, etc.
3.2.11 root-mean-square (rms)—the square root of the
mean-square value. In the exclusive case of a sine wave, the
4.7 Random vibration may be conducted in any axis (verti-
rms value is 0.707 times peak value.
cal or horizontal) or in any package orientation. However,
different test levels may be utilized for each axis depending on
3.2.12 sigma drive signal clipping—a condition where the
the field environment that is to be simulated.
maximumamplitudeofthedriveoroutputsignaltoavibration
systemislimitedtoasigmavalue,ormultipleofthermsvalue.
5. Apparatus
For drive clipping at the 3 sigma level, the maximum ampli-
tude will not exceed 3 times the rms value.
5.1 Vibration Test System—The vibration test system
(shaker) shall have a vibration table of sufficient strength and
3.2.13 sinusoidal vibration—a periodic oscillation having a
rigidity so that the applied vibrations are essentially uniform
sinusoidal waveform of only one frequency.
overtheentiretestsurfacewhenloadedwiththetestspecimen.
3.2.14 spectrum—a definition of the magnitude of the fre-
Thevibrationtableshallbesupportedbyamechanismcapable
quency components within a specified frequency range.
ofproducingsingleaxisvibrationinputsatcontrolledlevelsof
3.2.15 statistical degrees of freedom (DOF)—as related to
continuously variable amplitude throughout the desired range
PSD calculation, the degrees of freedom is a measure of the
of frequencies. Suitable fixtures and guides to restrict unde-
statisticalaccuracyofthePSDestimation.ThenumberofDOF
sired movement of the test specimens shall be provided.
isdeterminedbytheanalysisbandwidth(frequencyresolution)
5.2 Electronic Controls—Controlsshallprovidethecapabil-
and total time of the sample (determined by frequency resolu-
ity of generating vibration system drive inputs necessary to
tion and number of averages). It is defined by the formula
produce the desired power spectral density at the table surface
DOF=2BT, where B is the analysis bandwidth in Hz, and T is
adjacent to the test specimen.
the total record length in seconds.
5.2.1 Closed Loop–Automatic Equalization—A closed loop
3.2.16 transfer function—the dynamic relationship between
controller is required, which allows the operator to enter
output and input. In terms of a vibration system, it is the ratio desired PSD data. The controller automatically generates
ofoutputresponsetoaconstantinputoveradefinedfrequency
equalized vibration test system drive signals to achieve the
range. desired PSD thus maintaining closed loop control. The equal-
ized drive signals automatically compensate for specimen and
4. Significance and Use vibration test system characteristics. Typical systems include
an analog to digital converter for conditioning feedback
4.1 Shipping containers are exposed to complex dynamic
signals, a digital to analog converter to produce drive signals,
stresses in the distribution environment. Approximating the
a digital processor with real time analysis capability, random
actualdamage,orlackofdamage,experiencedinreallifemay
vibration control software programs, a graphics display
require subjecting the container and its contents to random
terminal, printer, and a data storage unit.
vibration tests. In this way, many product and container
resonances are simultaneously excited. NOTE 2—Random vibration systems typically create a drive signal that
D4728 − 17 (2022)
follows the Gaussian distribution. Many systems have a “drive clipping”
thenbereducedtoPSDformatandequalizedforpropercontrol
capability, which is sometimes employed to protect the vibration system
ofthevibrationsystem.IntheabsenceofspecifiedPSDdatait
or test specimen from high instantaneous amplitudes that might cause
is recommended that the appropriate profile from Appendix
damage.
X1, be used.
5.2.2 Thedigitalrealtimeanalysisshallprovideaminimum
8.3 Shaker table input levels to the test specimen provide
of 60 statistical degrees of freedom, and a maximum analysis
theonlycommonbenchmarkforrepeatabilitybetweenvarious
bandwidth of 2 Hz.
test systems. Therefore, control analysis based on monitoring
5.3 Instrumentation—Accelerometers, signal conditioners,
table motion rather than actual package response is recom-
analyzers, data display, storage devices, and the control tech-
mended. This table feedback signal is generated by an accel-
niquesdescribedin5.2arerequiredtomeasureandcontrolthe
erometer mounted directly to the table.Accelerometer mount-
PSD levels at the table surface. Instrumentation may also be
ing location should be next to the test specimen or directly
desirable for monitoring the response of the test specimen(s).
below it on the underside of the table.
The instrumentation system shall have an accuracy of 65%
8.4 Theshaker’sdrivesignalmustbeequalizedasdescribed
across the frequency range specified for the test.
in 5.2 to compensate for test specimen dynamics, the test
6. Safety Precautions system’s transfer function, and the control system’s transfer
function.
6.1 This test method may produce severe mechanical re-
8.4.1 The power spectral density of the random vibration
sponses of the test specimen(s). Therefore, fences, barricades,
testprofileshallnotdeviatefromthespecifiedrequirementsby
and other restraints must have sufficient strength and must be
more than 63 dB in any frequency analysis band over the
adequately secured. Operating personnel must remain alert to
entire test frequency range, except that deviations as large as
the potential hazards and take necessary precautions for their
66 dB will be allowed over a cumulative bandwidth of 10 Hz.
safety. Stop the test immediately if a dangerous condition
In addition, the overall g rms level shall not deviate more than
should develop.
615% from the specified level during the test.
8.4.2 The maximum equalizer analysis bandwidth allowed
7. Test Specimens
is 2 Hz and the minimum DOF is 60.
7.1 The test specimen shall consist of the container as
8.4.3 The equalizer analysis bandwidth may need to be less
intended for shipment, loaded with the interior packaging and
than2Hz,dependingontheslopeofthePSDbetweenadjacent
the actual contents for which it was designed. Blemished or
breakpoints. Very steep slopes require smaller bandwidths to
rejected products may be used if the defect will not affect test
maintain control to 63 dB.
results and if the defect is documented in the report. Dummy
8.4.4 If sigma drive signal clipping is used, the clipping
test loads are acceptable if testing the actual product might be
level used shall not be less than 3.0 sigma.
hazardous or cost prohibitive. If a dummy load is used, an
assessment must be made, after the test is completed, as to
9. Conditioning
whetherornottheactualtestitemwouldhavepassedorfailed.
9.1 Condition test specimens prior to the test or during the
Sensors and transducers should be applied with minimum
possible alteration of the test specimen to obtain data on the test, or both, in accordance with the requirements of the
applicable specification. When no conditioning requirements
containerorpackageditem.Whenitisnecessarytoobservethe
contents during the test, holes may be cut in noncritical areas aregiven,andthecontainermaterialsareclimaticallysensitive,
of the container. a conditioning atmosphere is recommended (see Practice
D4332 for standard and special conditions).
7.2 Whenever s
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.