ASTM F1797-98(2003)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:F1797–98 (Reapproved 2003)
Standard Test Method for
Acoustic Emission Testing of Insulated Digger Derricks
This standard is issued under the fixed designation F1797; 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 E569 Practice for Acoustic Emission Monitoring of Struc-
tures During Controlled Stimulation
1.1 This test method covers a procedure for acoustic emis-
2 2
E610 DefinitionsofTermsRelatingtoAcousticEmission
sion (AE) testing of insulated digger derricks.
E650 Guide for Mounting Piezoelectric Acoustic Emission
1.1.1 Equipment Covered—This test method applies to
Sensors
special multipurpose vehicle-mounted machines, commonly
E750 Practice for CharacterizingAcoustic Emission Instru-
known as digger derricks. These machines are primarily
mentation
designed to dig holes, set poles, and position materials and
E976 Guide for Determining the Reproducibility ofAcous-
apparatus.
tic Emission Sensor Response
1.1.1.1 Insulatedtypediggerderricksmaybeevaluatedwith
E1067 Practice for Acoustic Emission Examination of Fi-
this test method.
berglass Reinforced Plastic Resin (FRP) Tanks/Vessels
1.1.1.2 Diggerderricks,ifsoequippedtopositionpersonnel
F914 Test Method forAcoustic Emission for Insulated and
or equipment, or both, may also be evaluated with this test
Non-Insulated Aerial Personnel Devices Without Supple-
method in conjunction with Test Method F914.
mental Load Handling Attachments
1.1.2 Equipment Not Covered—Excluded from this test
2.2 Other Standards:
method are general-purpose cranes designed only for lifting
ASNT Recommended Practice SNT-TC-1A— Personnel
service and machines primarily designed only for digging
Qualification and Certification in Nondestructive Testing
holes.
ANSI A10.31 Digger Derricks—Safety Requirements,
1.2 The AE test method is used to detect and area-locate
Definitions, and Specifications
emissionsources.Verificationofemissionsourcesmayrequire
EMINomenclature and Specifications for Truck-Mounted
the use of other nondestructive test (NDT) methods, such as
Extensible Aerial Devices, Articulating Aerial Devices,
radiography,ultrasonic,magneticparticle,liquidpenetrant,and
Digger-Derricks
visual inspection.
1.3 Precaution—This test method requires that external
3. Terminology
loads be applied to the superstructure of the vehicle under test.
3.1 Definitions:
During the test, caution must be taken to safeguard personnel
3.1.1 acoustic emission, AE—the class of phenomena
and equipment against unexpected failure or instability of the
whereby elastic waves are generated by the rapid release of
vehicle or components.
energy from a localized source or sources within a material, or
1.4 This standard does not purport to address all of the
the transient elastic wave(s) so generated.
safety concerns, if any, associated with its use. It is the
3.1.1.1 Discussion—acoustic emission is the recommended
responsibility of the user of this standard to establish appro-
term for general use. Other terms that have been used in AE
priate safety and health practices and determine the applica-
literature include (1) stress wave emission, (2) microseismic
bility of regulatory limitations prior to use.
activity, and (3) emission or acoustic emission with other
2. Referenced Documents qualifying modifiers.
2.1 ASTM Standards:
This test method is under the jurisdiction of ASTM Committee F18 on
Electrical Protective Equipment for Workers and is the direct responsibility of Annual Book of ASTM Standards, Vol 10.03.
Subcommittee F18.55 on Inspection and Non-Destructive Test Methods for Aerial Available from American Society of Nondestructive Testing, 4153 Arlingate
Devices. Plaza, Caller #28518, Columbus, OH 43228.
Current edition approved Sept. 10, 2003. Published February 1999. Originally Available from the American National Standards Institute, 1430 Broadway,
published as F1797–97. Last previous edition F1797–97. DOI: 10.1520/F1797- New York, NY 10018.
98R03. AvailablefromtheEquipmentManufacturer’sInstitute,410N.MichiganAve.,
Annual Book of ASTM Standards, Vol 03.03. Chicago, IL 60611.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F1797–98 (2003)
FIG. 1 Insulated Digger Derrick Nomenclature
3.1.2 amplitude (acoustic emission signal amplitude)—the 3.1.9 event (acoustic emission event)—a local material
peak voltage of the largest excursion attained by the signal change giving rise to acoustic emission.
waveform from an emission event.
3.1.10 event count, N—the number obtained by counting
3.1.3 amplitude distribution—a display of the number of
each discerned acoustic emission event once.
acoustic emission events with signals that exceed an arbitrary
3.1.11 first-hit—a mode of operation of AE monitoring
amplitude as a function of amplitude.
equipment in which an event occurring on one channel will
3.1.4 attenuation—loss of energy per unit distance, typi-
prevent all other channels from processing data for a specified
cally measured as loss of signal peak amplitude with unit
period of time. The channel with a sensor closest to the
distance from the source of emission.
physical location of the emission source will then be the only
3.1.5 channel—an input to the main AE instrument that
channel processing data from that source.
accepts a preamplifier output.
3.1.12 insulator—anypartofthediggerderricksuchas,but
3.1.6 commoned—two or more sensors interconnected such
not limited to, any of the extensible boom sections or support-
that the sensor outputs are electronically processed by a single
ing structure, made of a material having a high dielectric
channel without differentiation of sensor origin. (syn. teed)
strength, usually FRP or the equivalent.
3.1.7 count, n—(acoustic emission count) the number of
3.1.13 noise—any undesired signal that tends to interfere
times the acoustic emission signal amplitude exceeds a preset
with the normal reception or processing of the desired signal.
threshold during any selected portion of a test.
3.1.14 qualified personnel—personnel who, by possession
3.1.8 decibel, dB—a reference scale that expresses the
of a recognized degree, certificate, professional standing, or
logarithmicratioofasignalpeakamplitudetoafixedreference
skill, and who, by knowledge, training, and experience, have
amplitude.
demonstrated the ability to deal with problems relating to the
A
subject matter, the work, or the project.
Signalpeakamplitude ~dB!520log (1)
A
0 3.1.15 signal (emission signal)—asignalobtainedbydetec-
tion of one or more acoustic emission events.
where:
3.1.16 For definitions of other terms in this test method,
A = 1 µV at the sensor output (before amplification), and
refer to Definitions E610 and the EMI Nomenclature and
A = peak voltage of the measured acoustic emission
Specifications.
signal.
3.2 Definitions of Terms Specific to the Standard:
3.2.1 auger—the hole-boring tool of the digger.
Acoustic Emission Reference Scale
3.2.2 authorized person—a qualified person approved and
Voltage At Voltage at Integral Preamp
dB Value Sensor Output Sensor Output (40 dB Gain) assignedbytheusertoperformaspecifictypeofdutyorduties
or to be at a specific location or locations at the job site.
0 1 µV 100 µV
20 10 µV 1 mV
3.2.3 boom angle indicator—a device that indicates the
40 100 µV 10 mV
angle between the boom and a horizontal plane.
60 1 mV 100 mV
80 10 mV 1 V 3.2.4 boom pin—the horizontal shaft about which the boom
100 100 mV 10 V
pivots as it is raised or lowered relative to the turntable.
F1797–98 (2003)
3.2.5 boom tip sheave—the sheave, located at the tip of a 3.2.29 turntable (F)—the structure above the rotation bear-
boom, that carries the winch line. ing that supports the booms.
3.2.6 capacity chart—a chart that indicates the load capac- 3.2.30 ultimate strength—for materials that do not have a
ity or rated capacity of the digger derrick, and by the choice of clearly defined yield strength, the stress level at which failure
the user reflects either the load capacity or the rated capacity. of a material will occur.
3.2.7 centerline of rotation—the vertical axis about which 3.2.31 upper boom (B)—the structural member that extends
the digger derrick rotates. the farthest, and that supports the boom tip sheave, or the
3.2.8 critical members—those components, members, or optional platform, or both.
structures in a digger derrick whose failure would cause 3.2.32 upper boom tip (A)—the end of the boom farthest
catastrophic failure of the digger derrick system. from the turntable.
3.2.9 design stress—the maximum stress at which the com-
4. Summary of Test Method
ponent is designed to operate under conditions of rated
capacity. 4.1 This test method consists of applying a predetermined
load to an insulated digger derrick while it is being monitored
3.2.10 digger—the mechanism that drives the auger.
bysensorsthataresensitivetoacousticemissions(AE)caused
3.2.11 extension cylinder—the hydraulic cylinder or cylin-
by active defects. These acoustic emissions can be generated
ders that extend the boom.
by, but are not limited to, the following: crack nucleation,
3.2.12 instability—aconditionofamobileunitinwhichthe
movement, or propagation in the metal components; or matrix
sum of the moments tending to overturn the unit is equal to or
crazing, delamination or fiber breakage of the fiber reinforced
exceeds the sum of the moments tending to resist overturning.
plastic (FRP) material, or both.
3.2.13 intermediate boom (C) —structural member or
4.2 The insulated digger derrick is loaded at a uniform rate
members that extend and are located between the upper and
until a predetermined load is reached, which is held for a
lower booms.
period of time. The load is removed and the cycle is repeated.
3.2.14 jib—an auxiliary boom that attaches to the upper
Acoustic emissions are monitored for the components being
boom tip to extend the reach of the boom.
evaluated during both cycles, and the data is reviewed.
3.2.15 lift cylinder—ahydrauliccylinderthatliftstheboom.
3.2.16 load block—a component consisting of a sheave or
5. Significance and Use
sheavesandahookthatisusedformultiplepartingoftheload
5.1 This test method permits testing of the major compo-
line.
nents of an insulated digger derrick shown inTable 1.The test
3.2.17 load capacity—the maximum load, specified by the
method provides a means of detecting acoustic emissions
manufacturer, that can be lifted by the mobile unit at regular
generatedbytherapidreleaseofenergyfromlocalizedsources
intervals of load radius and boom angle, through the specified
within the digger derrick under controlled loading.The energy
rangesofboomelevation,extension,androtation,withoptions
releases occur during intentional application of a predeter-
installed and inclusive of stability requirements.
mined load. These energy releases can be monitored and
3.2.18 load line—the load hoisting line.
interpreted by qualified individuals. Acceptance/rejection cri-
3.2.19 lower boom (D)—the structural member, attached to
teria are beyond the scope of this test method.The test may be
the turntable, that supports the extensible boom or booms.
discontinued at any time to investigate a particular area of
3.2.20 manufacturer—one who originally constructs the
concern, or to avoid imminent damage to the digger derrick
digger derrick.
resulting from the application of the test load.
3.2.21 model—manufacturer’s designation for digger der-
5.2 Significant sources of acoustic emission found with this
rick specified.
test method shall be evaluated by either more refined acoustic
3.2.22 operator—the person actually engaged in the opera-
emission test techniques or by other nondestructive methods
tion of the digger derrick.
(visual, liquid penetrant, radiography, ultrasonic, magnetic
3.2.23 outrigger cylinder—the hydraulic cylinder that ex-
tends the outrigger.
TABLE 1 Insulated Digger Derrick Components That May be
3.2.24 outriggers (L)—the structural members that are ex-
Monitored with Acoustic Emission
tended or deployed to assist in stabilizing the mobile unit.
Corresponding Letter in
3.2.25 pedestal (G)—the stationary base of the digger Component
Fig. 1
derrick that supports the turntable.
A
Upper Boom Tip A
3.2.26 platform (H)—the optional personnel-carrying com- A
Upper Boom B
ponent of a digger derrick, such as a bucket, basket, stand, or
Intermediate Boom(s), if equipped C
Lower Boom D
equivalent.
Lower Boom Lift Cylinder Attach Bracket E
3.2.27 platform pin—the horizontal pin about which the
Turntable F
optional platform rotates relative to the boom. Pedestal G
Optional Components—if equipped
3.2.28 structural components—those elements of a digger
Platform H
derrick that are subjected to stress during operation.
Platform Attachment I
A
Jib J
A
Jib Bracket/Cylinder Attach Bracket K
Outriggers L
7 A
Letters in parentheses refer to the corresponding letters in Table 1 and Fig. 1. These components must be monitored.
F1797–98 (2003)
particle, etc.). Other nondestructive methods may be required referenceamplitude.Thiswillestablishthemaximumeffective
inordertopreciselylocatedefectsinthediggerderrick,andto coverage of the sensor.
estimatetheirsize.Additionaltestsareoutsidethescopeofthis 8.4 The mounting of sensors shall be in accordance with
test method. PracticeE569andE650E569E650.Thecouplantusedshallnot
5.3 Defective areas found in digger derricks by this test affect the integrity of the digger derrick.
method should be repaired and retested as appropriate. Repair
NOTE 4—The couplant should be compatible with the digger derrick;
procedure recommendations are outside the scope of this test
notapossiblecauseofcontamination.Thecouplantshouldbecompletely
method.
removable from the surface after testing, leaving the original surface
intact.
6. Personnel Qualifications
9. AE Instrumentation System Performance Check
6.1 Thetestmethodshallbeperformedbyqualifiedperson-
9.1 Performance verification shall be made with an AE
nel. Qualification shall be in accordance with an established
simulator immediately prior to application of test load. This
written program prepared by a person familiar with design,
simulator should be capable of producing a transient elastic
manufacture, and operation of insulated digger derricks. The
wave having an amplitude representative of the AE signals to
program shall include an established format of ASNT SNT-
be recorded.
TC-1A
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