Standard Test Methods for Mechanical-Shock Fragility of Products, Using Shock Machines

SIGNIFICANCE AND USE
4.1 These test methods are intended to provide the user with data on product shock fragility that can be used in choosing optimum-cushioning materials for shipping containers or for product design modification.
SCOPE
1.1 These test methods cover determination of the shock fragility of products. This fragility information may be used in designing shipping containers for transporting the products. It may also be used to improve product ruggedness. Unit or consumer packages, which are transported within an outer container, are considered to be the product for the purposes of these test methods. Two test methods are outlined, as follows:  
1.1.1 Test Method A is used first, to determine the product's critical velocity change.  
1.1.2 Test Method B is used second, to determine the product's critical acceleration.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
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. For specific precautionary statements, see 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

Status
Published
Publication Date
30-Sep-2023
Technical Committee
Drafting Committee
Current Stage
Ref Project

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ASTM D3332-99(2023) - Standard Test Methods for Mechanical-Shock Fragility of Products, Using Shock Machines
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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: D3332 − 99 (Reapproved 2023)
Standard Test Methods for
Mechanical-Shock Fragility of Products, Using Shock
Machines
This standard is issued under the fixed designation D3332; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D2463 Test Method for Drop Impact Resistance of Blow-
Molded Thermoplastic Containers
1.1 These test methods cover determination of the shock
D3580 Test Methods for Vibration (Vertical Linear Motion)
fragility of products. This fragility information may be used in
Test of Products
designing shipping containers for transporting the products. It
D4332 Practice for Conditioning Containers, Packages, or
may also be used to improve product ruggedness. Unit or
Packaging Components for Testing
consumer packages, which are transported within an outer
D5112 Test Method for Vibration (Horizontal Linear Mo-
container, are considered to be the product for the purposes of
tion) Test of Products
these test methods. Two test methods are outlined, as follows:
E122 Practice for Calculating Sample Size to Estimate, With
1.1.1 Test Method A is used first, to determine the product’s
Specified Precision, the Average for a Characteristic of a
critical velocity change.
Lot or Process
1.1.2 Test Method B is used second, to determine the
E680 Test Method for Drop Weight Impact Sensitivity of
product’s critical acceleration.
Solid-Phase Hazardous Materials
1.2 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical
3. Terminology
conversions to SI units that are provided for information only
3.1 Definitions—General definitions for packing and distri-
and are not considered standard.
bution are found in Terminology D996.
1.3 This standard does not purport to address all of the
3.2 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
2 2
3.2.1 acceleration of gravity (g)—386.1 in./s (9.806 m/s ).
responsibility of the user of this standard to establish appro-
3.2.2 critical acceleration (A )—the maximum-faired accel-
priate safety, health, and environmental practices and deter-
c
mine the applicability of regulatory limitations prior to use. eration level for a minimum velocity change of 1.57 ΔV (see
c
9.3), above which product failure (or damage) occurs. A
For specific precautionary statements, see Section 6.
1.4 This international standard was developed in accor- product usually has a different critical acceleration for each
direction in which it is tested.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.2.3 critical velocity change (V )—the velocity change (see
c
Development of International Standards, Guides and Recom-
9.2) below which product failure is unaffected by shock-pulse
mendations issued by the World Trade Organization Technical
maximum-faired acceleration or waveform. A product usually
Barriers to Trade (TBT) Committee.
has a different critical velocity change for each direction in
which it is tested.
2. Referenced Documents
3.2.4 damage—product failure that occurs during a shock
2.1 ASTM Standards:
test. Damage can render the product unacceptable because it
D996 Terminology of Packaging and Distribution Environ-
becomes inoperable or fails to meet performance specifications
ments
when its appearance is unacceptably altered, or some combi-
nation of these failure modes occurs.
These test methods are under the jurisdiction of ASTM Committee D10 on
Packaging and are the direct responsibility of Subcommittee D10.13 on Interior 3.2.5 damage boundary—See Annex A3.
Packaging.
3.2.6 fairing—The graphical smoothing of the amplitude of
Current edition approved Oct. 1, 2023. Published October 2023. Originally
a recorded pulse still containing high frequency components
approved in 1988. Last previous edition approved in 2016 as D3332 – 99 (2016).
DOI: 10.1520/D3332-99R23.
even though electronic filtering may have been performed.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This amplitude is used to evaluate the basic recorded pulse
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
features with respect to the specified pulse. (see Figs. A1.1 and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. A2.1)
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3332 − 99 (2023)
3.2.7 shock pulse programmer—a device used to control the 6. Precautions
parameters of the acceleration versus time shock pulse gener-
6.1 These test methods may produce severe mechanical
ated by a shock test machine.
responses in the test specimen. Operating personnel must
3.2.8 shock test machine drop height—the distance through
therefore remain alert to potential hazards and take necessary
which the carriage of the shock test machine falls before
safety precautions. The test area should be cleared prior to each
striking the shock pulse programmer.
impact. The testing of hazardous material or products may
require special precautions that must be observed. Safety
4. Significance and Use
equipment may be required, and its use must be understood
4.1 These test methods are intended to provide the user with before starting the test.
data on product shock fragility that can be used in choosing
7. Sampling
optimum-cushioning materials for shipping containers or for
product design modification.
7.1 Sampling procedures and the number of test specimens
depend on the specific purposes and needs of the testing.
5. Apparatus
Sample size determination based on Practice E122 or other
5.1 Shock Test Machine: established statistical procedures is recommended.
5.1.1 The machine shall consist of a flat horizontal test
8. Conditioning
surface (carriage) of sufficient strength and rigidity to remain
flat and horizontal under the stresses developed during the test.
8.1 If temperature and humidity conditioning is required for
The test surface shall be guided to fall vertically without
the product being tested, refer to Practice D4332 for standard
rotation or translation in other directions.
conditioning procedures. Unless otherwise specified, conduct
5.1.2 The machine shall incorporate sufficient carriage drop
all tests with the same conditions prevailing.
height to produce the shock pulses given in 9.2 and 9.3. Drop
height control shall be provided to permit reproducibility 9. Procedure
within 60.25 in. (66 mm).
9.1 Mount the product to be tested on the carriage of the
5.1.3 The machine shall be equipped to produce shock
shock test machine. The product should be supported by a
pulses at the carriage as specified in 9.2 and 9.3.
fixture similar in shape and configuration to the cushion that
5.1.4 Means shall be provided to arrest the motion of the
will support the product in its shipping container. The fixture
carriage after impact to prevent secondary shock.
should be as rigid as possible so as not to distort the shock
5.2 Instrumentation: pulse imparted to the product. Fasten the fixture and product
securely to the carriage so that it will not leave the surface of
5.2.1 Acceleration—An accelerometer, signal conditioner,
and data storage apparatus are required to record acceleration- the carriage during the shock test.
time histories. The accelerometer shall be attached rigidly to
NOTE 1—The points at which the fixture supports the product are very
the base structure of the product or to the fixture, at or near a
important because the dynamic response of the product is influenced
point at which the fixture is fastened to the carriage. If the strongly by the location of these support points
NOTE 2—If the orientation of the product can change during handling
fixture is sufficiently rigid to not distort the shock pulse
impacts, a test may be required for each of the directions in which the
imparted to the product, the accelerometer may be mounted on
input shock can occur. Multidirectional tests are recommended since most
the carriage. In some cases, when a product contains heavy
products have different fragilities in different orientations.
resiliently supported masses that will distort the shock pulses
9.2 Test Method A—Critical Velocity Change Shock Test:
severely, it may be necessary to precalibrate the shock ma-
9.2.1 Scope—This test method is used to determine the
chine. The accelerometer is fastened to the carriage in this case,
critical velocity change (V ) portion of the damage boundary
c
and a rigid mass weighing the same as the product is subjected
plot of a product.
to a series of shock pulses. The instrumentation system shall
9.2.1.1 To ensure that the components of a product only
have sufficient response to permit measurements in the follow-
respond to the velocity change of the pulse, a shock pulse
ing ranges.
having any waveform and a duration (T ) not longer than 3 ms
p
5.2.1.1 Test Method A—5 Hz or less to at least 1000 Hz.
should be used to perform this test. Pulse durations as short as
5.2.1.2 Test Method B—1 Hz or less to at least 330 Hz.
0.5 ms may be required when testing small, very rigid products
5.2.1.3 Accuracy—Reading to be within 65 % of the actual
(see Note 3). Shock pulse waveform is not limited since the
value.
critical velocity portion of the damage boundary is unaffected
5.2.1.4 Cross-Axis Sensitivity—Less than 5 % of the actual
by shock pulse shape. Since they are relatively easy to control,
value.
shock pulses having a half sine shock waveform are normally
5.2.2 Velocity—Instrumentation to measure the velocity
used.
change of the shock table is required. This may be a device that
integrates the area electronically under the shock pulse wave- NOTE 3—In general: T ≤ 167 / f
p c
form. Alternatively, it can be measured by photodiode-type
where:
devices that measure shock table impact and rebound velocity.
T = maximum shock test machine pulse duration in ms, and
p
Calculation that assumes the shock pulse to be a perfect
f = component natural frequency in Hz.
c
geometric figure is usually grossly inaccurate and should not be
For example, a component of a product with a natural frequency below
used. 56 Hz can be effectively tested on a shock machine with a 3 ms duration
D3332 − 99 (2023)
pulse. If the component natural frequency is higher, the pulse duration
9.3.2.2 Perform one shock test.
must be shorter. A 2 ms duration pulse can be used on a component with
9.3.2.3 Examine the recorded shock pulse to be certain the
a natural frequency up to 83 Hz.
desired maximum-faired acceleration and velocity change were
9.2.2 Procedure:
obtained.
9.2.2.1 Set the shock test machine so that the shock pulse
9.3.2.4 Examine or functionally test the product, or do both,
produced has a velocity change below the anticipated critical
to determine whether damage due to shock has occurred.
velocity change of the product.
9.3.2.5 If no damage has occurred, set the shock test
9.2.2.2 Perform one shock test.
machine for a higher maximum-faired acceleration level. Be
9.2.2.3 Examine or functionally test the product, or do both, certain that the velocity change of subsequent shock pulses is
to determine whether damage due to shock has occurred. maintained at or above the level determined in 9.3.2.1. Accept-
able increment size is influenced strongly by the product being
9.2.2.4 If no damage has occurred, set the shock test
machine for a higher velocity change and repeat the shock test. tested. For example, an increment of 5 g may be appropriate for
most products but unacceptable for high-value products.
Acceptable increment size is influenced strongly by the product
being tested. For example, an increment of 5 in./s (0.13 m/s)
NOTE 4—See shock machine manufacturer recommendations for setting
may be appropriate for most products but unacceptable for
acceleration levels because this procedure is specific to the type of
high-value products. programmer.
9.2.2.5 Repeat 9.2.2.2 – 9.2.2.4, with incrementally increas-
9.3.2.6 Repeat 9.3.2.2 – 9.3.2.5, with incrementally increas-
ing velocity change, until product damage occurs. This point is
ing maximum-faired acceleration, until product damage oc-
shown as Test No. 7 in Fig. A3.1.
curs. This point is shown as Test No. 14 in Fig. A3.1. Common
9.2.2.6 Common practice is to define the critical velocity
practice is to define the critical acceleration (A ) as the
c
change (V ) as the midpoint between the last successful test and
c midpoint between the last successful test and the test that
the test that produced failure. Depending on the purpose of the
produced failure. Depending on the purpose of the test, use of
test, use of the last successful test point before failure may be
the last successful test point before failure may be considered
considered as a more conservative estimate of (V ).
c as a more conservative estimate of (A ).
c
9.3 Test Method B—Critical Acceleration Shock Test:
10. Report
9.3.1 Scope—This test method is used to determine the
10.1 Report the following information:
critical acceleration (A ) portion of the damage boundary plot
c
10.1.1 Reference to these test methods, noting any devia-
of a product.
tions from the test method.
9.3.1.1 When the critical acceleration of a product is known,
10.1.2 Complete identification of the product being tested,
package cushioning materials can be chosen to protect it.
including type, manufacturer’s code numbers, general descrip-
9.3.1.2 If no cushioning materials are to be used in the
tion of configuration, and its pretest condition.
package, it may be unnecessary to perform this test. Only the
10.1.3 Method of mounting the product on the carriage of
critical velocity change test may suffice in this case.
the shock test machine.
9.3.1.3 Trapezoidal shock pulses are normally used to
10.1.4 Type of instrumentation used and critical settings
perform this test. Although a true square wave shock pulse is
thereof.
most desirable in theory, it is not possible to obtain infinitely
10.1.5 Recordings of the shock pulses that caused product
short rise and fall times. On the basis of much testing
damage.
experience, it has been determined that rise and fall times (see
10.1.6 Record of shock test machine drop height for each
Fig. A2.1) of 1.8 ms, or less, are req
...

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