ASTM F1797-98

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 1797 – 98
Standard Test Method for
Acoustic Emission Testing of Insulated Digger Derricks
This standard is issued under the fixed designation F 1797; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope E 650 Guide for Mounting Piezoelectric Acoustic Emission
Contact Sensors
1.1 This test method covers a procedure for acoustic emis-
E 750 Practice for Characterizing Acoustic Emission Instru-
sion (AE) testing of insulated digger derricks.
mentation
1.1.1 Equipment Covered—This test method applies to
E 976 Guide for Determining the Reproducibility of Acous-
special multipurpose vehicle-mounted machines, commonly
tic Emission Sensor Response
known as digger derricks. These machines are primarily
E 1067 Practice for Acoustic Emission Examination of
designed to dig holes, set poles, and position materials and
Fiberglass Reinforced Plastic Resin (FRP) Tanks/Vessels
apparatus.
F 914 Test Method for Acoustic Emission for Insulated
1.1.1.1 Insulated type digger derricks may be evaluated with
Aerial Personnel Devices
this test method.
2.2 Other Standards:
1.1.1.2 Digger derricks, if so equipped to position personnel
ASNT Recommended Practice SNT-TC-1A— Personnel
or equipment, or both, may also be evaluated with this test
Qualification and Certification in Nondestructive Testing
method in conjunction with Test Method F 914.
ANSI A10.31 Digger Derricks—Safety Requirements,
1.1.2 Equipment Not Covered—Excluded from this test
Definitions, and Specifications
method are general-purpose cranes designed only for lifting
EMI Nomenclature and Specifications for Truck-Mounted
service and machines primarily designed only for digging
Extensible Aerial Devices, Articulating Aerial Devices,
holes.
Digger-Derricks
1.2 The AE test method is used to detect and area-locate
emission sources. Verification of emission sources may require
3. Terminology
the use of other nondestructive test (NDT) methods, such as
3.1 Definitions:
radiography, ultrasonic, magnetic particle, liquid penetrant, and
3.1.1 acoustic emission, AE—the class of phenomena
visual inspection.
whereby elastic waves are generated by the rapid release of
1.3 Precaution—This test method requires that external
energy from a localized source or sources within a material, or
loads be applied to the superstructure of the vehicle under test.
the transient elastic wave(s) so generated.
During the test, caution must be taken to safeguard personnel
3.1.1.1 Discussion—acoustic emission is the recommended
and equipment against unexpected failure or instability of the
term for general use. Other terms that have been used in AE
vehicle or components.
literature include (1) stress wave emission, (2) microseismic
1.4 This standard does not purport to address all of the
activity, and (3) emission or acoustic emission with other
safety concerns, if any, associated with its use. It is the
qualifying modifiers.
responsibility of the user of this standard to establish appro-
3.1.2 amplitude (acoustic emission signal amplitude)—the
priate safety and health practices and determine the applica-
peak voltage of the largest excursion attained by the signal
bility of regulatory limitations prior to use.
waveform from an emission event.
2. Referenced Documents 3.1.3 amplitude distribution—a display of the number of
acoustic emission events with signals that exceed an arbitrary
2.1 ASTM Standards:
amplitude as a function of amplitude.
E 569 Practice for Acoustic Emission Monitoring of Struc-
3.1.4 attenuation—loss of energy per unit distance, typi-
tures During Controlled Stimulation
2 cally measured as loss of signal peak amplitude with unit
E 610 Definitions of Terms Relating to Acoustic Emission
distance from the source of emission.
Annual Book of ASTM Standards, Vol 10.03.
This test method is under the jurisdiction of ASTM Committee F-18 on
Available from American Society of Nondestructive Testing, 4153 Arlingate
Electrical Protective Equipment for Workers and is the direct responsibility of Plaza, Caller #28518, Columbus, OH 43228.
Subcommittee F18.55 on Acoustic Emission. Available from the American National Standards Institute, 1430 Broadway,
Current edition approved Nov. 10, 1998. Published February 1999. Originally New York, NY 10018.
published as F 1797–97. Last previous edition F 1797–97. Available from the Equipment Manufacturer’s Institute, 410 N. Michigan Ave.,
Annual Book of ASTM Standards, Vol 03.03. Chicago, IL 60611.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 1797
FIG. 1 Insulated Digger Derrick Nomenclature
3.1.5 channel—an input to the main AE instrument that 3.1.12 insulator—any part of the digger derrick such as, but
accepts a preamplifier output. not limited to, any of the extensible boom sections or support-
3.1.6 commoned—two or more sensors interconnected such ing structure, made of a material having a high dielectric
that the sensor outputs are electronically processed by a single strength, usually FRP or the equivalent.
channel without differentiation of sensor origin. (syn. teed)
3.1.13 noise—any undesired signal that tends to interfere
3.1.7 count, n—(acoustic emission count) the number of
with the normal reception or processing of the desired signal.
times the acoustic emission signal amplitude exceeds a preset
3.1.14 qualified personnel—personnel who, by possession
threshold during any selected portion of a test.
of a recognized degree, certificate, professional standing, or
3.1.8 decibel, dB—a reference scale that expresses the
skill, and who, by knowledge, training, and experience, have
logarithmic ratio of a signal peak amplitude to a fixed reference
demonstrated the ability to deal with problems relating to the
amplitude.
subject matter, the work, or the project.
A
1 3.1.15 signal (emission signal)—a signal obtained by detec-
Signal peak amplitude ~dB!5 20 log (1)
A
tion of one or more acoustic emission events.
3.1.16 For definitions of other terms in this test method,
where:
refer to Definitions E 610 and the EMI Nomenclature and
A = 1 μV at the sensor output (before amplification), and
Specifications.
A = peak voltage of the measured acoustic emission
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
assigned by the user to perform a specific type of duty or duties
dB Value Sensor Output Sensor Output (40 dB Gain)
or to be at a specific location or locations at the job site.
0 1 μV 100 μV
3.2.3 boom angle indicator—a device that indicates the
20 10 μV 1 mV
angle between the boom and a horizontal plane.
40 100 μV 10 mV
60 1 mV 100 mV
3.2.4 boom pin—the horizontal shaft about which the boom
80 10 mV 1 V
pivots as it is raised or lowered relative to the turntable.
100 100 mV 10 V
3.2.5 boom tip sheave—the sheave, located at the tip of a
3.1.9 event (acoustic emission event)—a local material
boom, that carries the winch line.
change giving rise to acoustic emission.
3.2.6 capacity chart—a chart that indicates the load capac-
3.1.10 event count, N—the number obtained by counting
ity or rated capacity of the digger derrick, and by the choice of
each discerned acoustic emission event once.
the user reflects either the load capacity or the rated capacity.
3.1.11 first-hit—a mode of operation of AE monitoring
3.2.7 centerline of rotation—the vertical axis about which
equipment in which an event occurring on one channel will
the digger derrick rotates.
prevent all other channels from processing data for a specified
period of time. The channel with a sensor closest to the 3.2.8 critical members—those components, members, or
physical location of the emission source will then be the only structures in a digger derrick whose failure would cause
channel processing data from that source. catastrophic failure of the digger derrick system.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 1797
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
4.1 This test method consists of applying a predetermined
capacity.
load to an insulated digger derrick while it is being monitored
3.2.10 digger—the mechanism that drives the auger.
by sensors that are sensitive to acoustic emissions (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—a condition of a mobile unit in which the
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—a hydraulic cylinder that lifts the boom.
5. Significance and Use
3.2.16 load block—a component consisting of a sheave or
5.1 This test method permits testing of the major compo-
sheaves and a hook that is used for multiple parting of the load
nents of an insulated digger derrick shown in Table 1. The test
line.
method provides a means of detecting acoustic emissions
3.2.17 load capacity—the maximum load, specified by the
generated by the rapid release of energy from localized sources
manufacturer, that can be lifted by the mobile unit at regular
within the digger derrick under controlled loading. The energy
intervals of load radius and boom angle, through the specified
releases occur during intentional application of a predeter-
ranges of boom elevation, extension, and rotation, with options
mined load. These energy releases can be monitored and
installed and inclusive of stability requirements.
interpreted by qualified individuals. Acceptance/rejection cri-
3.2.18 load line—the load hoisting line.
teria are beyond the scope of this test method. The test may be
3.2.19 lower boom (D)—the structural member, attached to
discontinued at any time to investigate a particular area of
the turntable, that supports the extensible boom or booms.
concern, or to avoid imminent damage to the digger derrick
3.2.20 manufacturer—one who originally constructs the
resulting from the application of the test load.
digger derrick.
5.2 Significant sources of acoustic emission found with this
3.2.21 model—manufacturer’s designation for digger der-
test method shall be evaluated by either more refined acoustic
rick specified.
emission test techniques or by other nondestructive methods
3.2.22 operator—the person actually engaged in the opera-
(visual, liquid penetrant, radiography, ultrasonic, magnetic
tion of the digger derrick.
particle, etc.). Other nondestructive methods may be required
3.2.23 outrigger cylinder—the hydraulic cylinder that ex-
in order to precisely locate defects in the digger derrick, and to
tends the outrigger.
estimate their size. Additional tests are outside the scope of this
3.2.24 outriggers (L)—the structural members that are ex-
test method.
tended or deployed to assist in stabilizing the mobile unit.
5.3 Defective areas found in digger derricks by this test
3.2.25 pedestal (G)—the stationary base of the digger
method should be repaired and retested as appropriate. Repair
derrick that supports the turntable.
procedure recommendations are outside the scope of this test
3.2.26 platform (H)—the optional personnel-carrying com-
method.
ponent of a digger derrick, such as a bucket, basket, stand, or
equivalent. 6. Personnel Qualifications
3.2.27 platform pin—the horizontal pin about which the
6.1 The test method shall be performed by qualified person-
optional platform rotates relative to the boom.
nel. Qualification shall be in accordance with an established
3.2.28 structural components—those elements of a digger
TABLE 1 Insulated Digger Derrick Components That May be
derrick that are subjected to stress during operation.
Monitored with Acoustic Emission
3.2.29 turntable (F)—the structure above the rotation bear-
Corresponding Letter in
ing that supports the booms. Component
Fig. 1
3.2.30 ultimate strength—for materials that do not have a
A
Upper Boom Tip A
clearly defined yield strength, the stress level at which failure A
Upper Boom B
Intermediate Boom(s), if equipped C
of a material will occur.
Lower Boom D
3.2.31 upper boom (B)—the structural member that extends
Lower Boom Lift Cylinder Attach Bracket E
the farthest, and that supports the boom tip sheave, or the
Turntable F
Pedestal G
optional platform, or both.
Optional Components—if equipped
3.2.32 upper boom tip (A)—the end of the boom farthest
Platform H
from the turntable.
Platform Attachment I
A
Jib J
A
Jib Bracket/Cylinder Attach Bracket K
Outriggers L
A
Letters in parentheses refer to the corresponding letters in Table 1 and Fig. 1. These components must be monitored.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F 1797
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 for training, qualification, and certification of personnel 9.2 The AE simulator may be gas jet, pencil lead b
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