1、Designation:D7249/D7249M20Standard Test Method forFacesheet Properties of Sandwich Constructions by LongBeam Flexure1This standard is issued under the fixed designation D7249/D7249M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the
2、 year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers determination of facesheetproperties of flat sandwich constructions subjected to flexure i
3、nsuch a manner that the applied moments produce curvature ofthe sandwich facesheet planes and result in compressive andtensile forces in the facesheets.Permissible core material formsinclude those with continuous bonding surfaces(such as balsawood and foams)as well as those with discontinuous bondin
4、gsurfaces(such as honeycomb).1.2 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard.Thevalues stated in each system are not necessarily exact equiva-lents;therefore,to ensure conformance with the standard,eachsystem shall be used independently of
5、the other,and valuesfrom the two systems shall not be combined.1.2.1 Within the text,the inch-pound units are shown inbrackets.1.3 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 appr
6、o-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1Alternate procedures for determining the compressivestrength of unidirectional polymer matrix composites materials in asandwich beam configuration may be found in Test Meth
7、od D5467/D5467M.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization Techn
8、icalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2C273/C273M Test Method for Shear Properties of SandwichCore MaterialsC393/C393M Test Method for Core Shear Properties ofSandwich Constructions by Beam FlexureD3410/D3410M Test Method for Compressive Properties ofPolymer Ma
9、trix Composite Materials with UnsupportedGage Section by Shear LoadingD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsD5467/D5467M Test Method for Compressive Properties ofUnidirecti
10、onal Polymer Matrix Composite Materials Us-ing a Sandwich BeamD7250/D7250M Practice for Determining Sandwich BeamFlexural and Shear StiffnessE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE122 Practice for Calculating Sample Size to Est
11、imate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE251 Test Methods for Performance Characteristics of Me-tallic Bonded Resistance Strain GagesE456 Terminology Relating to Quality and StatisticsE1
12、237 Guide for Installing Bonded Resistance Strain Gages3.Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto high-modulus fibers and their composites.Terminology E6defines terms relating to mechanical testing.Terminology E456and Practice E177 define terms relating to statistics.In t
13、heevent of a conflict between terms,Terminology D3878 shallhave precedence over the other terminologies.1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich Construction.Current edition approved Feb
14、.1,2020.Published February 2020.Originallyapproved in 2006.Last previous edition approved in 2018 as D7249/D7249M 18.DOI:10.1520/D7249_D7249M-20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volu
15、me information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardiza
16、tion established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 Copyright by ASTM Intl(all rights reserved);Tue Feb 25 21:47:41 EST 2020Downloaded/printed byPurdue University Libraries(Purdue University Libraries)pursuant to License Agreement.No further reproductions authorized.3.2 Symbols:b=specimen widthc=core thicknessCV=coefficient of variation statistic