ASTM_D_7336_-_D_7336M_-_16.pdf

Designation:D7336/D7336M16Standard Test Method forStatic Energy Absorption Properties of HoneycombSandwich Core Materials1This standard is issued under the fixed designation D7336/D7336M;the number immediately following the designation indicates theyear 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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method determines the static energy absorptionproperties(compressive crush stress and crush stroke)ofhoneycomb sandwich core materials.These properties areusually determined for design purposes in a direction normal tothe plane of facings as the honeycomb core material would beplaced in a structural sandwich construction.1.2 Permissible core materials are limited to those in hon-eycomb form.1.3 This test method is not intended for use in crush testingof stabilized honeycomb core materials(for which the facingplane surfaces of the honeycomb core material are dipped inresin to resist local crushing)or sandwich specimens(forwhich facings are bonded to the honeycomb core material).1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately 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.1.4.1 Within the text the inch-pound units are shown inbrackets.1.5 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:2C271/C271M Test Method for Density of Sandwich CoreMaterialsD883 Terminology Relating to PlasticsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and Statistics3.Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto high-modulus fibers and their composites,as well as termsrelating to sandwich constructions.Terminology D883 definesterms relating to plastics.Terminology E6 defines termsrelating to mechanical testing.Terminology E456 and PracticeE177 define terms relating to statistics.In the event of aconflict between terms,Terminology D3878 shall have prece-dence over the other terminologies.NOTE1If the term represents a physical quantity,its analyticaldimensions are stated immediately following the term(or letter symbol)infundamental dimension form,using the following ASTM standard sym-bology for fundamental dimensions,shown within square brackets:Mfor mass,L for length,T for time,for thermodynamic temperature,and nd for non-dimensional quantities.Use of these symbols is restrictedto analytical dimensions when used with square brackets,as the symbolsmay have other definitions when used without the brackets.3.2 Definitions of Terms Specific to This Standard:3.2.1 cell size L,nin a honeycomb core,the distancebetween two parallel and opposite cell walls at node bondareas,measured transverse to the ribbon direction.3.2.2 node bond area,nin a honeycomb core,the areabetween two cells at which the component walls of the cells arebonded or attached.3.3 Symbols: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 April 1,2016.Published April 2016.Originallyapproved in 2007.Last previous edition approved in 2012 as D7336/D7336M 12.DOI:10.1520/D7336_D7336M-16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 A=cross-sectional area of a test specimen prior to com-pressive crush testingCV=coefficient of variation statistic of a sample populationfor a given property(in percent)KA=initial chord slope of the force versus displacement/deformation curveKB=post-crush slope of the force versus displacement/deformation curvePcr=average force carried by test specimen during com-pressive crushingscr=crush stroke in percentSn