ASTM E1888 E1888M-2007 Standard Practice for Acoustic Emission Examination of Pressurized Containers Made of Fiberglass Reinforced Plastic with Balsa Wood Cores《带巴沙(Balsa)木芯的玻璃纤维增强.pdf

1、Designation: E 1888/E 1888M 07Standard Practice forAcoustic Emission Examination of Pressurized ContainersMade of Fiberglass Reinforced Plastic with Balsa WoodCores1This standard is issued under the fixed designation E 1888/E 1888M; the number immediately following the designation indicates theyear

2、of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers guidelines for acoustic emission(A

3、E) examinations of pressurized containers made of fiberglassreinforced plastic (FRP) with balsa cores. Containers of thistype are commonly used on tank trailers for the transport ofhazardous chemicals.1.2 This practice is limited to cylindrical shape containers,0.5 m 20 in. to 3 m 120 in. in diamete

4、r, of sandwichconstruction with balsa wood core and over 30 % glass (byweight) FRP skins. Reinforcing material may be mat, roving,cloth, unidirectional layers, or a combination thereof. There isno restriction with regard to fabrication technique or method ofdesign.1.3 This practice is limited to con

5、tainers that are designedfor less than 0.520 MPa 75.4 psi (gage) above static pressurehead due to contents.1.4 This practice does not specify a time interval betweenexaminations for re-qualification of a pressure container.1.5 This practice is used to determine if a container issuitable for service

6、or if follow-up NDT is needed before thatdetermination can be made.1.6 Containers that operate with a vacuum are not within thescope of this practice.1.7 Repair procedures are not within the scope of thispractice.1.8 The values stated in either SI units or inch-pound unitsare to be regarded separate

7、ly as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.9 This standard does not purport to address all of thesafety concerns, i

8、f any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 8.2. Referenced Documents2.1 AST

9、M Standards:2E 543 Specification for Agencies Performing Nondestruc-tive TestingE 750 Practice for CharacterizingAcoustic Emission Instru-mentationE 976 Guide for Determining the Reproducibility of Acous-tic Emission Sensor ResponseE 1067 Practice for Acoustic Emission Examination ofFiberglass Reinf

10、orced Plastic Resin (FRP) Tanks/VesselsE 1316 Terminology for Nondestructive ExaminationsE 2374 Guide for Acoustic Emission System PerformanceVerification2.2 SPI/CARP Standards:3Recommended Practice for Acoustic Emission Testing ofFiberglass Reinforced Plastic Resin (FRP) Tanks/VesselsRecommended Pr

11、actice for Acoustic Emission Testing ofFiberglass Reinforced Plastic Piping Systems2.3 ANSI/ASNT Standards:4SNT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestructive TestingANSI/ASNT CP-189 Standard for Qualification and Certi-fication of NDT Personnel2.4 AIA St

12、andard:NAS-410 Nondestructive Testing Personnel Qualificationand Certification51This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.04 onAcoustic Emission Method.Current edition approved July 1, 2007. Published

13、 July 2007. Originally approvedin 1997. Last previous edition approved in 2002 as E 1888/E 1888M - 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards

14、Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:

15、/www.asnt.org.5Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.5 ASME Standar

16、d:Section V, Article 11, Boiler and Pressure Vessel Code63. Terminology3.1 DefinitionsWith the exception of terms defined in 3.2,this practice incorporates by reference all terminology inTerminology E 1316 and Practice E 1067. First occurrences ofterms defined herein are italicized.3.2 Definitions o

17、f Terms Specific to This Standard:3.2.1 AE trend numbera number used to designate trendsin AE activity which are exhibited by structures during a set ofrepeated loading cycles (see 9.2).3.2.2 Minimum AE activity levelthat level of activitybelow which AE trend numbers are not robust indicators of the

18、trend (see 9.1)3.2.3 Examination pressurethe highest pressure usedwhile examining a given container. The examination pressureis 1.1 times the maximum allowable working pressure, MAWP(see Section 8).4. Significance and Use4.1 This practice does not rely on absolute quantities of AEparameters. It reli

19、es on trends of cumulativeAE counts that aremeasured during a specified sequence of loading cycles. Thispractice includes an example of examination settings andacceptance criteria as a nonmandatory appendix.4.2 Acoustic emission (AE) counts were used as a measureofAE activity during development of t

20、his practice. Cumulativehit duration may be used instead of cumulative counts if acorrelation between the two is determined. Several processescan occur within the structure under examination. Some mayindicate unacceptable flaws (for example, growing resincracks, fiber fracture, delamination). Others

21、 may produce AEbut have no structural significance (for example, rubbing atinterfaces). The methodology described in this practice pre-vents contamination of structurally significant data with emis-sion from insignificant sources.4.3 Background NoiseBackground noise can distort inter-pretations of A

22、E data and can preclude completion of anexamination. Examination personnel should be aware ofsources of background noise at the time examinations areconducted. AE examinations should not be conducted untilsuch noise is substantially eliminated.4.4 Mechanical Background NoiseMechanical back-ground no

23、ise is generally induced by structural contact with thecontainer under examination. Examples are: personnel contact,wind borne sand or rain. Also, leaks at pipe connections mayproduce background noise.4.5 Electronic NoiseElectronic noise such as electromag-netic interference (EMI) and radio frequenc

24、y interference(RFI) can be caused by electric motors, overhead cranes,electrical storms, welders, etc.4.6 Airborne Background NoiseAirborne backgroundnoise can be produced by gas leaks in nearby equipment.4.7 Accuracy of the results from this practice can beinfluenced by factors related to setup and

25、 calibration ofinstrumentation, background noise, material properties, andstructural characteristics.5. Basis of Application5.1 The following items are subject to contractual agree-ment between the parties using or referencing this practice.5.2 Personnel Qualification:5.2.1 If specified in the contr

26、actual agreement, personnelperforming examinations to this practice shall be qualified inaccordance with a nationally or internationally recognized6Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme

27、.org.FIG. 1 Recommended Features of the ApparatusE 1888/E 1888M 072NDT personnel qualification practice or standard such asANSI/ASNT CP-189, SNT-TC-1A, NAS-410, or a similardocument and certified by the employer or certifying agency,as applicable. The practice or standard used and its applicablerevi

28、sion shall be identified in the contractual agreement be-tween the using parties.5.2.2 Also, it is required that personnel performing acousticemission examination of containers be trained, by attending adedicated training course on the subject and passing a writtenexamination. The training course sh

29、all include appropriatematerial for NDT Level II qualification in accordance with arecognized NDT personnel qualification practice or standardper 5.2.1. Personnel shall be trained/examined on the followingtopics:5.2.2.1 Container construction and terminology,5.2.2.2 Mechanisms of AE generation in FR

30、P includingcontainers within the scope of this practice,5.2.2.3 AE instrumentation,5.2.2.4 Container examination procedures, including load-ing requirements,5.2.2.5 Data collection and interpretation, and5.2.2.6 Examination report and permanent record require-ments.5.3 Qualification of Nondestructiv

31、e AgenciesIf specifiedin the contractual agreement, NDT agencies shall be qualifiedand evaluated as described in Practice E 543. The applicableedition of Practice E 543 shall be specified in the contractualagreement.5.4 Timing of ExaminationThe timing of examinationshall be in accordance with 1.4-1.

32、7 unless otherwise specified.5.5 Procedures and TechniquesThe procedures and tech-niques to be utilized shall be specified in the contractualagreement.5.6 Extent of ExaminationThe extent of examination shallbe in accordance with paragraph 1.2, unless otherwise speci-fied.5.7 Reporting Criteria/Accep

33、tance CriteriaReportingcriteria/acceptance criteria shall be in accordance with Sections9 and 10 unless otherwise specified.5.8 Reexamination of Repaired/Reworked ItemsReexamination of repaired/reworked items is not addressed inthis practice and if required shall be specified in the contractualagree

34、ment.6. Apparatus6.1 Recommended features of the apparatus required forthis practice are provided in Fig. 1. Full specifications are inAnnex A1.6.2 Couplant must be used to acoustically connect sensorsto the vessel surface. Adhesives that have acceptable acousticproperties and adhesives used in comb

35、ination with traditionalcouplants are acceptable.6.3 Sensors may be held in place with elastic straps,adhesive tape, or other mechanical means.6.4 Sensor spacing shall be such that a standard 0.5 mm, 2Hpencil lead break (See Guide E 976) on any part of a liquidfilled container is detected by at leas

36、t oneAE sensor.A0.3 mm,2H pencil lead break may be used which would reduce thesensor spacing. Presence of heads, manholes, and nozzles shallbe considered when sensor locations are selected. Fig. 2 showsa typical sensor location scheme for a vessel of 10.8 m 424 in.length and 1.8 m 72 in. diameter.6.

37、4.1 Attenuation CharacterizationTypical signal propa-gation losses shall be determined according to the followingprocedure. This procedure provides a relative measure of theattenuation but may not be representative of a genuine AEsource. It should be noted that the peak amplitude from amechanical pe

38、ncil lead break may vary with surface hardness,resin condition and cure. Select a representative region of thevessel with clear access along the cylindrical section. Mount anAE sensor and mark off distances of 15 cm (6 in.) and 30 cm(12 in.) from the center of the sensor along a line parallel to the

39、principal direction of the surface fiber. Select two additionalpoints on the surface of the vessel at 15 cm (6 in.) and 30 cm(12 in.) along a line inclined 45 and 90 to the principaldirection of the surface fiber, break pencil leads (0.3 mm 2H,rather then 0.5 mm to avoid possible saturation due to l

40、argersignal output) and record peak amplitude. All lead breaks shallbe done at an angle of approximately 30 to the surface with a2.54 mm 0.1 in. lead extension. The attenuation data shall beretained as part of the original experimental record.6.4.2 In addition, record the distances from the center o

41、f thesensor to the points where hits are no longer detected. Repeatthis procedure along lines inclined 45 and 90 to the directionof the original line. The data shall be retained as part of theoriginal experimental record. The minimum distance from theFIG. 2 Typical Examination Configuration Showing

42、AE Sensor Location on a Road TankerE 1888/E 1888M 073sensor at which the pencil lead break can no longer be detectedis known as the threshold distance.6.5 Acoustic emission sensors are used to detect straininduced stress waves produced by discontinuities. Sensorsmust be held in contact with the vess

43、el wall to ensure adequateacoustic coupling.6.6 A preamplifier may be enclosed in the sensor housing orin a separate enclosure. If a separate preamplifier is used, cablelength between sensor and preamplifier must not exceed 2 m78 in.6.7 Power/signal cable length (that is, cable between pream-plifier

44、 and signal processor) shall not exceed 150 m 500 ft.6.8 Signal processors are computerized instruments withindependent channels that filter, measure and convert analoginformation into digital form for display and permanent stor-age.Asignal processor must have sufficient speed and capacityto indepen

45、dently process data from all sensors simultaneously.The signal processor should provide capability to filter data forreplay.6.9 A video monitor should display processed data invarious formats. Display format may be selected by theexaminer.6.10 Adata storage device, such as a hard disc or removableme

46、dia (CD, DVD, or other), may be used to provide data forreplay or for archives.6.11 Hard copy capability should be available from a printeror equivalent output device.7. Calibration and System Performance Verification7.1 Perform annual calibration and verification of pressuretransducer, AE sensors,

47、preamplifiers (if applicable), signalprocessor (particularly the signal processor time reference) andAE electronic waveform generator. Adjust equipment so that itconforms to equipment manufacturers specifications. Instru-ments used for calibrations must have current accuracy certi-fication that is t

48、raceable to the National Institute for Standardsand Technology (NIST).7.2 Perform routine electronic evaluations on a monthlybasis or at any time there is concern about signal processorperformance. Use an AE electronic waveform generator inmaking evaluations. Each signal processor channel must re-sp

49、ond with peak amplitude reading within 62dBoftheexpected output value (based on input signal value andamplifier gain values).7.3 Perform routine evaluation of each sensor on a monthlybasis or at any time there is concern about the sensorsperformance. Record peak amplitude response and electronicnoise level. Sensors can be stimulated by a pencil lead break orelectronic waveform generator with a pulser. Replace sensorsthat are found to have peak amplitudes or electronic noise morethan 5 dB greater or less than the average of the group ofsensors t