1、Designation:F1645/F1645M16Standard Test Method forWater Migration in Honeycomb Core Materials1This standard is issued under the fixed designation F1645/F1645M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.
2、A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of watermigration in honeycomb core materials.1.2 The values stated in either SI units or inch
3、-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 un
4、its 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
5、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 MatrixComposi
6、te MaterialsE122 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 DefinitionsTermino
7、logy D3878 defines terms relatingto high-modulus fibers and their composites,as well as termsrelating to structural sandwich constructions.TerminologyD883 defines terms relating to plastics.Terminology E456 andPractice E177 define terms relating to statistics.In the event ofa conflict between terms,
8、Terminology D3878 shall haveprecedence over the other terminologies.3.2 Symbols:CV=coefficient of variation statistic of a sample populationfor a given property(in percent),Sn-1=standard deviation statistic of a sample population fora given property,x1=test result for an individual specimen from the
9、 samplepopulation for a given property,x=mean or average(estimate of mean)of a samplepopulation for a given property,Vc=volume of water necessary to fill one core cell,Vf=volume of water transfused,Wc=mass of specimen after filling the primary cell withwater,Wf=mass of specimen after water transfusi
10、on,andWi=mass of specimen after conditioning,prior to waterintroduction.4.Summary of Test Method4.1 This test method consists of bonding a honeycomb corematerial to transparent facings using a water-resistant adhesive,drilling an access hole through one facing to an individual corecell,filling the c
11、ell with water,subjecting the filled cell to aconstant hydrostatic pressure by maintaining a specified watercolumn height,then measuring the amount of water transferredinto the honeycomb core specimen(primarily due to diffusionthrough the cell walls)within a 24-h period.The amount ofwater transferre
12、d is presented as an approximate number ofhoneycomb core cells filled with water.5.Significance and Use5.1 Water permeability is a fundamental physical propertythat can be used in conjunction with other properties tocharacterize honeycomb sandwich core materials.Migrationtesting can be used to chara
13、cterize and compare the relativepermeability of honeycomb core materials to water.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 Ma
14、y 2016.Originallyapproved in 1995.Last previous edition approved in 2012 as F1645 12.DOI:10.1520/F1645_F1645M-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 stan
15、dards 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 This test method provides a standard method of charac-terizing the rate of water migration within honeycomb sand-wichcorematerialsfordesign
16、properties,materialspecifications,research and development applications,andquality assurance.5.3 Factors that influence water migration rate characteris-tics of honeycomb sandwich core materials and shall thereforebe reported include the following:core material,methods ofmaterial fabrication,core geometry(cell size),core thickness,core thickness uniformity,cell wall thickness,specimengeometry,specimen preparation,specimen conditioning,fac-ing material,facing permeability,adhesive permeability,ad
