ASTM_E_1495_-_E_1495M_-_12.pdf

Designation:E1495/E1495M12Standard Guide forAcousto-Ultrasonic Assessment of Composites,Laminates,and Bonded Joints1This standard is issued under the fixed designation E1495/E1495M;the number immediately following the designation indicates the yearof 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*1.1 This guide explains the rationale and basic technologyfor the acousto-ultrasonic(AU)method.Guidelines are givenfor nondestructive evaluation(NDE)of flaws and physicalcharacteristics that influence the mechanical properties andrelative strength of composite structures(for example,filament-wound pressure vessels),adhesive bonds(forexample,joints between metal plates),and interlaminar andfiber/matrix bonds in man-made composites and natural com-posites(for example,wood products).1.2 This guide covers technical details and rules that mustbe observed to ensure reliable and reproducible quantitativeAU assessments of laminates,composites,and bonded struc-tures.The underlying principles,prototype apparatus,instrumentation,standardization,examination methods,anddata analysis for such assessments are covered.Limitations ofthe AU method and guidelines for taking advantage of itscapabilities are cited.1.3 The objective of AU is to assess subtle flaws andassociated strength variations in composite structures andbonded joints.Discontinuities such as large voids,disbonds,orextended lack of contact at interfaces can be assessed by otherNDE methods such as conventional ultrasonics.1.4 Additional information may be found in the publicationscited in the list of references at the end of this guide.Thereferencedworksprovidebackgroundonresearch,applications,and various aspects of signal acquisition,processing,and interpretation.1.5 UnitsThe values stated in either SI units or inch-pound units are to be regarded 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 standards.1.6 This standard does not purport to address all of thesafety concerns,if 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.2.Referenced Documents2.1 ASTM Standards:2E543 Specification for Agencies Performing NondestructiveTestingE1316 Terminology for Nondestructive Examinations2.2 ASNT Standard:3ANSI/ASNT CP-189 Standard for Qualification and Certifi-cation of Nondestructive Testing PersonnelSNT-TC-1A Recommended Practicem for Personnel Quali-fications and Certification in Nondestructive Testing2.3 AIA Document:4NAS-410 Certification and Qualification of NondestructiveTesting Personnel3.Terminology3.1 Definitions:3.1.1 acousto-ultrasonics(AU)a nondestructive examina-tion method that uses induced stress waves to detect and assessthe diffuse defect states,damage conditions,and variations ofmechanical properties of an examination structure.The AUmethod combines aspects of acoustic emission(AE)signalanalysis with ultrasonic materials characterization methods(Terminology E1316).3.1.2 Additional related definitions may be found in Termi-nology E1316.3.2 Definitions of Terms Specific to This Standard:1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.04 on AcousticEmission Method.Current edition approved June 15,2012.Published July 2012.Originallyapproved in 1992.Last previous edition approved in 2007 as E1495-02(2007).DOI:10.1520/E1495-12.2For 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 Document Summary page onthe ASTM website.3Available fromAmerican Society for Nondestructive Testing(ASNT),P.O.Box28518,1711 Arlingate Ln.,Columbus,OH 43228-0518,http:/www.asnt.org.4Available from Aerospace Industries Association of America,Inc.(AIA),1000Wilson Blvd.,Suite 1700,Arlington,VA22209-3928,http:/www.aia-aerospace.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.1 stress wave factor(SWF)a generic measure of therelative energy loss(attenuation)or propagation efficiency ofstress waves generated by the AU method.There are manyways to define and calculate the SWF.Several of these aredescribed in Section 11 of this guide.4.Summary of Guide4.1 GeneralTwo probes are attached to a sample in asend-receive configuration.One(a pulsed sending probe)isoptimized for wave generation,while the other(a receivingprobe)is optimized for signal sen