ASTM_D_8388_-_D_8388M_-_22.pdf

Designation:D8388/D8388M22Standard Practice forFlexural Residual Strength Testing of Damaged SandwichConstructions1This standard is issued under the fixed designation D8388/D8388M;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 practice provides instructions for modifying thelong beam flexure test method to determine the tensile orcompressive residual strength properties of sandwich construc-tions that have been subjected to quasi-static indentation ordrop-weight impact per Practice D7766/D7766M.The tensileor compressive strength result is determined by whichfacesheet contains the damage,either the loaded-span orsupport-span facesheet,based on how the specimen is posi-tioned in the fixture.1.2 This practice supplements Test Method D7249/D7249Mwith provisions for testing damaged sandwich specimens.Several important test specimen parameters(for example,facesheet thickness,core thickness and core density)are notmandated by this practice;however,repeatable results requirethat these parameters be specified and reported.1.3 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 the other,and valuesfrom the two systems shall not be combined.1.3.1 Within the text,the inch-pound units are shown inbrackets.1.4 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 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 TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD3410/D3410M Test Method for Compressive Properties ofPolymer Matrix Composite Materials with UnsupportedGage Section by Shear LoadingD3878 Terminology for Composite MaterialsD5687/D5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionD7249/D7249M Test Method for Facesheet Properties ofSandwich Constructions by Long Beam FlexureD7766/D7766M Practice for Damage Resistance Testing ofSandwich ConstructionsE6 Terminology Relating to Methods of Mechanical TestingE122 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 symbols1This practice is under the jurisdiction of ASTM Committee D30 on CompositeMaterials and is the direct responsibility of Subcommittee D30.09 on SandwichConstruction.Current edition approved May 1,2022.Published June 2022.DOI:10.1520/D8388_D8388M-22.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization 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.1may have other definiti