ASTM_C_366_-_C_366M_-_16.pdf

Designation:C366/C366M16Standard Test Methods forMeasurement of Thickness of Sandwich Cores1This standard is issued under the fixed designation C366/C366M;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods cover plant manufacturing proce-dures for measuring the thickness of flat sandwich cores.Permissible core material forms include those with continuousbonding surfaces(such as balsa wood and foams)as well asthose with discontinuous bonding surfaces(such as honey-comb).The two test methods covered include the following:1.1.1 Test Method ARoller-Type Thickness Tester.1.1.2 Test Method BDisk-Type Thickness Tester.NOTE1These test methods are designed for measuring thickness ofcore as it is produced and are not intended for use in determiningdimensions of core specimens for other tests.1.2 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.1.2.1 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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or ProcessE171 Practice for Conditioning and Testing Flexible BarrierPackagingE177 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 E456 and Practice E177define terms relating to statistics.In the event of a conflictbetween terms,Terminology D3878 shall have precedenceover the other terminologies.3.2 Symbols:3.2.1 CVcoefficient of variation statistic of a samplepopulation for a given property(in percent)3.2.2 Sn-1standard deviation statistic of a sample popula-tion for a given property3.2.3 Xitest result for an individual specimen from thesample population for a given property3.2.4 x mean or average(estimate of mean)of a samplepopulation for a given property4.Summary of Test Methods4.1 These test methods consist of environmentally condi-tioning a sandwich core specimen,zeroing a thickness tester,placing the core underneath the tester,and measuring the corethickness by sliding the core underneath the tester.Proceduresare provided for thickness measurement using both roller-typeand disk-type thickness testers.5.Significance and Use5.1 Normally,a close tolerance is desirable for core thick-ness so that sandwich panels may be manufactured with all thesandwich components fitting properly and without crushing thecore.1These test methods are under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich Construction.Current edition approved March 15,2016.Published March 2016.Originallyapproved in 1955.Last previous edition approved in 2011 as C366 11.DOI:10.1520/C0366_C0366M-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 5.2 These test methods are designed for measuring thick-ness of core as it is produced and are not intended for use indetermining dimensions of core specimens for other tests.5.3 These test methods provide standard methods of obtain-ing the core thickness of flat sandwich core materials,andprovide a basis for determining average thickness dimensions.The thickness properties derived may be used in designproperties,material specifications,research and developmentapplications,and quality assurance.5.4 Factors that influence core thickness measurement andshall therefore be reported include the following:core materialthr