ASTM_C_364_-_C_364M_-_16.pdf

Designation:C364/C364M16Standard Test Method forEdgewise Compressive Strength of SandwichConstructions1This standard is issued under the fixed designation C364/C364M;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.1.Scope1.1 This test method covers the compressive properties ofstructural sandwich construction in a direction parallel to thesandwich facing plane.Permissible core material forms includethose with continuous bonding surfaces(such as balsa woodand foams)as well as those with discontinuous bondingsurfaces(such as honeycomb).1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.Within the text theinch-pound units are shown in brackets.The values stated ineach system are not exact equivalents;therefore,each systemmust be used independently of the other.Combining valuesfrom the two systems may result in nonconformance with thestandard.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:D792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD2584 Test Method for Ignition Loss of Cured ReinforcedResinsD2734 Test Methods for Void Content of Reinforced PlasticsD3039/D3039M Test Method for Tensile Properties of Poly-mer Matrix Composite MaterialsD3171 Test Methods for Constituent Content of CompositeMaterialsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsD5687/D5687M Guide for Preparation of Flat CompositePanels with Processing Guidelines for Specimen Prepara-tionE4 Practices for Force Verification of Testing MachinesE6 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 StatisticsE1012 Practice for Verification of Testing Frame and Speci-men Alignment Under Tensile and Compressive AxialForce Application3.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.Terminolgoy 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.3.2 Symbols:b=width of specimenCV=coefficient of variation statistic of a sample populationfor a given property(in percent)L=length of specimenP=force on specimenSn-1=standard deviation statistic of a sample population fora given propertytc=core thicknesstfs=nominal facesheet thicknessxi=test result for an individual specimen from the samplepopulation for a given propertyx5mean or average(estimate of mean)of a samplepopulation for a given property=facesheet compressive stress1This 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 1955.Last previous edition approved in 2012 as C364/C364M 07(2012).DOI:10.1520/C0364_C0364M-16.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Test Method4.1 This test method consists of subjecting a sandwich panelto monotonically increasing compressive force parallel to theplane of its faces.The force is transmitted to the panel througheither clamped or bonded end supports.Stress and strength arereported in terms of the nominal cross-sectional area of the twofacesheets,rather than total sandwich panel thickness,althoughalternate stress calculations may be optionally specified.4.2 The only acceptable failure modes for edgewise com-pressive strength of sandwich constructions are those occurringaway from the supported ends.The sandwich column,nomatter how short,usually is subjected to a buckling type offailure unless the facings are so thick that they themselves arein the short column class.The failure of the facings manifestsitself by wrinkling of the facing,in which the core deforms tothe wavy shape of the facings;by dimpling of the facings intothe honeycomb cells;by bending of the sandw