ASTM D3332-99(2004)
(Test Method)Standard Test Methods for Mechanical-Shock Fragility of Products, Using Shock Machines
Standard Test Methods for Mechanical-Shock Fragility of Products, Using Shock Machines
SIGNIFICANCE AND USE
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 either inch-pound or SI units are to be regarded as the standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Section .
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:D3332–99 (Reapproved 2004)
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 D4332 Practice for Conditioning Containers, Packages, or
Packaging Components for Testing
1.1 These test methods cover determination of the shock
D5112 Test Method for Vibration (Horizontal Linear Mo-
fragility of products. This fragility information may be used in
tion) Test of Products
designing shipping containers for transporting the products. It
E122 Practice for Calculating Sample Size to Estimate,
may also be used to improve product ruggedness. Unit or
With Specified Precision, the Average for a Characteristic
consumer packages, which are transported within an outer
of a Lot or Process
container, are considered to be the product for the purposes of
E680 Test Method for Drop Weight Impact Sensitivity Of
these test methods. Two test methods are outlined, as follows:
Solid-Phase Hazardous Materials
1.1.1 Test MethodAis used first, to determine the product’s
critical velocity change.
3. Terminology
1.1.2 Test Method B is used second, to determine the
3.1 Definitions—General definitions for packing and distri-
product’s critical acceleration.
bution are found in Terminology D996.
1.2 The values stated in either inch-pound or SI units are to
3.2 Definitions of Terms Specific to This Standard:
be regarded as the standard. The values given in parentheses
2 2
3.2.1 acceleration of gravity (g)—386.1 in./s (9.806 m/s ).
are for information only.
3.2.2 critical acceleration (A )—themaximum-fairedaccel-
c
1.3 This standard does not purport to address all of the
eration level for a minimum velocity change of 1.57 DV (see
c
safety concerns, if any, associated with its use. It is the
9.3), above which product failure (or damage) occurs. A
responsibility of the user of this standard to establish appro-
product usually has a different critical acceleration for each
priate safety and health practices and determine the applica-
direction in which it is tested.
bility of regulatory limitations prior to use. For specific
3.2.3 critical velocity change (V )—thevelocitychange(see
c
precautionary statements, see Section 6.
9.2) below which product failure is unaffected by shock-pulse
2. Referenced Documents maximum-faired acceleration or waveform. A product usually
2 has a different critical velocity change for each direction in
2.1 ASTM Standards:
which it is tested.
D996 Terminology of Packaging and Distribution Environ-
3.2.4 damage—product failure that occurs during a shock
ments
test. Damage can render the product unacceptable because it
D2463 Test Method for Drop Impact Resistance of Blow-
becomes inoperable or fails to meet performance specifications
Molded Thermoplastic Containers
when its appearance is unacceptably altered, or some combi-
D3580 Test Methods for Vibration (Vertical Linear Motion)
nation of these failure modes occurs.
Test of Products
3.2.5 damage boundary—See Annex A3.
3.2.6 fairing—The graphical smoothing of the amplitude of
These test methods are under the jurisdiction of ASTM Committee D10 on
a recorded pulse still containing high frequency components
Packaging and are the direct responsibility of Subcommittee D10.15 on Fragility
even though electronic filtering may have been performed.
Assessment.
This amplitude is used to evaluate the basic recorded pulse
Current edition approved Oct. 1, 2004. Published October 2004. Originally
features with respect to the specified pulse. (see Figs.A1.1 and
approved in 1988. Last previous edition approved in 1999 as D3332 – 99. DOI:
10.1520/D3332-99R04.
A2.1)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.2.7 shock pulse programmer—adeviceusedtocontrolthe
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
parameters of the acceleration versus time shock pulse gener-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ated by a shock test machine.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3332–99 (2004)
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 safetyprecautions.Thetestareashouldbeclearedpriortoeach
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
optimum-cushioning materials for shipping containers or for
7. Sampling
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
surface (carriage) of sufficient strength and rigidity to remain
8. Conditioning
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
5.2.1 Acceleration— An accelerometer, signal conditioner,
securely to the carriage so that it will not leave the surface of
and data storage apparatus are required to record acceleration-
the carriage during the shock test.
time histories. The accelerometer shall be attached rigidly to
the base structure of the product or to the fixture, at or near a
NOTE 1—The points at which the fixture supports the product are very
point at which the fixture is fastened to the carriage. If the
important because the dynamic response of the product is influenced
fixture is sufficiently rigid to not distort the shock pulse strongly by the location of these support points
NOTE 2—If the orientation of the product can change during handling
imparted to the product, the accelerometer may be mounted on
impacts, a test may be required for each of the directions in which the
the carriage. In some cases, when a product contains heavy
input shock can occur. Multidirectional tests are recommended since most
resiliently supported masses that will distort the shock pulses
products have different fragilities in different orientations.
severely, it may be necessary to precalibrate the shock ma-
9.2 Test Method A—Critical Velocity Change Shock Test:
chine.Theaccelerometerisfastenedtothecarriageinthiscase,
9.2.1 Scope—This test method is used to determine the
and a rigid mass weighing the same as the product is subjected
critical velocity change ( V ) portion of the damage boundary
to a series of shock pulses. The instrumentation system shall
c
plot of a product.
have sufficient response to permit measurements in the follow-
9.2.1.1 To ensure that the components of a product only
ing ranges.
respond to the velocity change of the pulse, a shock pulse
5.2.1.1 Test Method A— 5 Hz or less to at least 1000 Hz.
having any waveform and a duration (T ) not longer than 3 ms
5.2.1.2 Test Method B— 1 Hz or less to at least 330 Hz. p
should be used to perform this test. Pulse durations as short as
5.2.1.3 Accuracy—Reading to be within 65 % of the actual
0.5 ms may be required when testing small, very rigid products
value.
(see Note 3). Shock pulse waveform is not limited since the
5.2.1.4 Cross-Axis Sensitivity—Less than 5 % of the actual
critical velocity portion of the damage boundary is unaffected
value.
by shock pulse shape. Since they are relatively easy to control,
5.2.2 Velocity—Instrumentation to measure the velocity
shock pulses having a half sine shock waveform are normally
changeoftheshocktableisrequired.Thismaybeadevicethat
used.
integrates the area electronically under the shock pulse wave-
form. Alternatively, it can be measured by photodiode-type
NOTE 3—In general: T # 167 / f
p c
devices that measure shock table impact and rebound velocity.
where:
Calculation that assumes the shock pulse to be a perfect
T = maximum shock test machine pulse duration in ms, and
p
geometricfigureisusuallygrosslyinaccurateandshouldnotbe
f = component natural frequency in Hz.
c
used.
For example, a component of a product with a natural frequency below
56 Hz can be effectively tested on a shock machine witha3ms duration
6. Precautions
pulse. If the component natural frequency is higher, the pulse duration
6.1 These test methods may produce severe mechanical
must be shorter. A 2 ms duration pulse can be used on a component with
responses in the test specimen. Operating personnel must a natural frequency up to 83 Hz.
D3332–99 (2004)
9.2.2 Procedure: 9.3.2.3 Examine the recorded shock pulse to be certain the
desiredmaximum-fairedaccelerationandvelocitychangewere
9.2.2.1 Set the shock test machine so that the shock pulse
obtained.
produced has a velocity change below the anticipated critical
9.3.2.4 Examine or functionally test the product, or do both,
velocity change of the product.
to determine whether damage due to shock has occurred.
9.2.2.2 Perform one shock test.
9.3.2.5 If no damage has occurred, set the shock test
9.2.2.3 Examine or functionally test the product, or do both,
machine for a higher maximum-faired acceleration level. Be
to determine whether damage due to shock has occurred.
certain that the velocity change of subsequent shock pulses is
9.2.2.4 If no damage has occurred, set the shock test
maintained at or above the level determined in 9.3.2.1.Accept-
machine for a higher velocity change and repeat the shock test.
able increment size is influenced strongly by the product being
Acceptableincrementsizeisinfluencedstronglybytheproduct
tested.Forexample,anincrementof5gmaybeappropriatefor
being tested. For example, an increment of 5 in./s (0.13 m/s)
most products but unacceptable for high-value products.
may be appropriate for most products but unacceptable for
NOTE 4—See shock machine manufacturer recommendations for set-
high-value products.
ting acceleration levels because this procedure is specific to the type of
9.2.2.5 Repeat 9.2.2.2-9.2.2.4, with incrementally increas-
programmer.
ing velocity change, until product damage occurs.This point is
9.3.2.6 Repeat 9.3.2.2-9.3.2.5, with incrementally increas-
shown as Test No. 7 in Fig. A3.1.
ing maximum-faired acceleration, until product damage oc-
9.2.2.6 Common practice is to define the critical velocity
curs.This point is shown asTest No. 14 in Fig.A3.1. Common
change(V )asthemidpointbetweenthelastsuccessfultestand
c
practice is to define the critical acceleration (A)asthe
c
the test that produced failure. Depending on the purpose of the
midpoint between the last successful test and the test that
test, use of the last successful test point before failure may be
produced failure. Depending on the purpose of the test, use of
considered as a more conservative estimate of (V ).
c
the last successful test point before failure may be considered
9.3 Test Method B—Critical Acceleration Shock Test:
as a more conservative estimate of (A ).
c
9.3.1 Scope—This test method is used to determine the
10. Report
critical acceleration ( A ) portion of the damage boundary plot
c
of a product.
10.1 Report the following information:
10.1.1 Reference to these test methods, noting any devia-
9.3.1.1 Whenthecriticalaccelerationofaproductisknown,
tions from the test method.
package cushioning materials can be chosen to protect it.
10.1.2 Complete identification of the product being tested,
9.3.1.2 If no cushioning materials are to be used in the
including type, manufacturer’s code numbers, general descrip-
package, it may be unnecessary to perform this test. Only the
tion of configuration, and its pretest condition.
critical velocity change test may suffice in this case.
10.1.3 Method of mounting the product on the carriage of
9.3.1.3 Trapezoidal shock pulses are normally used to
the shock test machine.
perform this test. Although a true square wave shock pulse is
10.1.4 Type of instrumentation used and critical settings
most desirable in theory, it is not possible to obtain infinitely
thereof.
short rise and fall times. On the basis of much testing
10.1.5 Recordings of the shock pulses that caused product
experience, it has been determined that rise and fall times (see
damage.
Fig.A2.1) of 1.8 ms, or less, are required. Longer rise and fall
10.1.6 Record of shock test machine drop height for each
times cause the critical acceleration line of the damage
shock pulse that caused product damage.
boundary curve to deviate from the horizontal, introducing
10.1.7 Record of damage, including a photograph of prod-
errors into the test results. For the same reason, waveforms
uct damage, if visible.
havingfairedshapesthatarenottrapezoidalshouldnotbeused
10.1.8 Record of waveform, maximum-faired acceleration,
for this test.Their use would cause the critical acceleration line
pulse duration, and velocity change of the shock pulses.
of the damage boundary curve to vary widely as a function of
10.1.9 Record of conditioning used.
velocity change. For example, if a half sine shock pulse
10.1.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.