1、Designation: C363/C363M 09 (Reapproved 2015)Standard Test Method forNode Tensile Strength of Honeycomb Core Materials1This standard is issued under the fixed designation C363/C363M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, t
2、he 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 determination of the tensile-node bond strength of honeycomb core materials.1.2
3、 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
4、 standard.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. Re
5、ferenced Documents2.1 ASTM Standards:2C274 Terminology of Structural Sandwich ConstructionsD883 Terminology Relating to PlasticsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsE4 Pra
6、ctices 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 Tes
7、t MethodsE456 Terminology Relating to Quality and StatisticsE1309 Guide for Identification of Fiber-ReinforcedPolymer-Matrix Composite Materials in DatabasesE1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in DatabasesE1471 Guide for Identification of Fibers, Fi
8、llers, and CoreMaterials in Computerized Material Property Databases3. Terminology3.1 DefinitionsTerminology D3878 defines terms relatingto high-modulus fibers and their composites. TerminologyC274 defines terms relating to structural sandwich construc-tions. Terminology D883 defines terms relating
9、to plastics.Terminology E6 defines terms relating to mechanical testing.Terminology E456 and Practice E177 define terms relating tostatistics. In the event of a conflict between terms, TerminologyD3878 shall have precedence over the other Terminologies.3.2 Symbols:3.2.1 tensile node strength, MPa ps
10、i.3.2.2 Pultimate tensile force, N lb.3.2.3 binitial width of specimen, mm in.3.2.4 tthickness of specimen, mm in.3.2.5 xsample mean (average).3.2.6 Sn1sample standard deviation.3.2.7 CVsample coefficient of variation (in percent).3.2.8 nnumber of specimens.3.2.9 x1measured or derived property.4. Su
11、mmary of Test Method4.1 This test method consists of subjecting a honeycombconstruction to a uniaxial tensile force parallel to the plane ofthe honeycomb. The force is transmitted to the honeycombthrough pins, which are placed in cell rows on the top andbottom portions of one specimen.4.2 The only a
12、cceptable failure mode for tensile-node bondstrength is the tensile failure of the node-to-node honeycombbond within the body of the honeycomb specimen. Failure ofthe honeycomb material at the loading pin location is not avalid failure mode.5. Significance and Use5.1 The honeycomb tensile-node bond
13、strength is a funda-mental property than can be used in determining whetherhoneycomb cores can be handled during cutting, machining1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich Construction.C
14、urrent edition approved July 1, 2015. Published August 2015. Originallyapproved in 1955. Last previous edition approved in 2009 as C363 09. DOI:10.1520/C0363_C0363M-09R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Ann
15、ual 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 States1and forming without the nodes breaking. The tensile-nodebond strength is the
16、 tensile stress that causes failure of thehoneycomb by rupture of the bond between the nodes. It isusually a peeling-type failure.5.2 This test method provides a standard method of obtain-ing tensile-node bond strength data for quality control, accep-tance specification testing, and research and dev
17、elopment.6. Interferences6.1 System AlignmentExcessive bending will cause pre-mature failure. Every effort should be made to eliminate excessbending from the test system. Bending may occur as a result ofmisaligned grips, poor specimen preparation, or poor align-ment of the loading fixture.6.2 Geomet
18、rySpecific geometric factors that affect thetensile-node bond strength include cell geometry, cell size, cellwall thickness and, specimen dimensions (length, width andthickness).6.3 EnvironmentResults are affected by the environmentalconditions under which the tests are conducted. Specimenstested in
19、 various environments can exhibit significant differ-ences in both strength behavior and failure mode. Criticalenvironments must be assessed independently.7. Apparatus7.1 Testing MachineThe testing machine shall be in ac-cordance with Practices E4 and shall satisfy the followingrequirements:7.1.1 Te
20、sting Machine ConfigurationThe testing machineshall have both an essentially stationary head and a movablehead.7.1.2 Drive MechanismThe testing machine drive mecha-nism shall be capable of imparting to the movable head acontrolled velocity with respect to the stationary head. Thevelocity of the mova
21、ble head shall be capable of beingregulated in accordance with 11.3.7.1.3 Force IndicatorThe testing machine load-sensingdevice shall be capable of indicating the total force beingcarried by the test specimen. This device shall be essentiallyfree from inertia lag at the specified rate of testing and
22、 shallindicate the force with an accuracy over the force range(s) ofinterest of within 61 % of the indicated value.7.2 GripsRefer to Fig. 1 for an example grip configura-tion.7.3 CalipersThe caliper(s) shall use a flat anvil interfaceto measure specimen length, width and thickness. The accuracyof th
23、e instruments shall be suitable for reading to within1%ofthe sample width and thickness. For typical specimengeometries, an instrument with an accuracy of 625 m60.001 in. is desirable for both thickness and width mea-surements.8. Sampling and Test Specimens8.1 SamplingThe number of test specimens an
24、d themethod of their selection depend on the purpose of theparticular test under consideration, and no general rule can begiven to cover all cases. However, when specimens are to beused for acceptance tests, at least five specimens shall betested, and these specimens shall be selected from that port
25、ionof the material which appears to have a maximum of distortedcells or misalignment of bond areas. For statistically significantdata, consult the procedures outlined in Practice E122. Reportthe method of sampling.8.2 GeometryThe test specimens shall be 130 6 5mm56 0.2 in. wide. The test specimens s
26、hall have a minimumlength of 260 10 in. with a minimum test section outside thegrips of 200 mm 8 in. The standard thickness of the coreslice shall be 12 6 1 mm 0.500 6 0.04 in. for nonmetalliccores and 16 6 1 mm 0.625 6 0.04 in. for metallic cores.Nonstandard thicknesses are within the scope of this
27、 testmethod provided the actual thickness value is reported. Non-standard thickness specimens shall have uniform thicknesswithin 61mm60.04 in.NOTE 1The standard thickness values listed above are based onhistorical values for metallic and nonmetallic core thicknesses used forqualification and allowab
28、le test programs.8.3 Specimen Preparation and MachiningSpecimensshall be cut such that the number of cells along the width isconstant along the specimen length. The length being definedas the specimen dimension parallel to the application of theforce, Fig. 1. The specimen width shall be parallel to
29、the nodebond areas.FIG. 1 Honeycomb Core Tensile-Node Bond Strength Test SetupC363/C363M 09 (2015)28.4 LabelingLabel the test specimens so that they will bedistinct from each other and traceable back to the panel oforigin, and will neither influence the test nor be affected by it.9. Calibration9.1 T
30、he accuracy of all measuring equipment shall havecertified calibrations that are current at the time of the use ofthe equipment.10. Conditioning10.1 The recommended pre-test condition is effective mois-ture equilibrium at a specific relative humidity as establishedby Test Method D5229/D5229M; howeve
31、r, if the test requestordoes not explicitly specify a pre-test conditioning environment,no conditioning is required and the test specimens may betested as prepared.10.2 The pre-test specimen conditioning process, to includespecified environmental exposure levels and resulting moisturecontent, shall
32、be reported with the test data.NOTE 2The term “moisture,” as used in Test Method D5229/D5229M, includes not only the vapor of a liquid and its condensate, butthe liquid itself in large quantities, as for immersion.10.3 If no explicit conditioning process is performed, thespecimen conditioning proces
33、s shall be reported as “uncondi-tioned” and the moisture content as “unknown.”11. Procedure11.1 Parameters to be Specified Before Test:11.1.1 The specimen sampling method, specimen geometry,and conditioning travelers (if required).11.1.2 The properties and data reporting format desired.NOTE 3Determi
34、ne specific material property, accuracy, and datareporting requirements prior to test for proper selection of instrumentationand data recording equipment. Estimate the specimen strength to aid intransducer selection, calibration of equipment, and determination ofequipment settings.11.1.3 The environ
35、mental conditioning test parameters.11.1.4 If performed, sampling method, specimen geometry,and test parameters used to determine facing density andreinforcement volume.11.2 General Instructions:11.2.1 Report any deviations from this test method, whetherintentional or inadvertent.11.2.2 Following fi
36、nal specimen machining and anyconditioning, but before testing, measure the specimen lengthand width. The accuracy of these measurements shall be within0.5 % of the dimension. Measure the specimen thickness; theaccuracy of this measurement shall be within 625 m 60.001in.). Record the dimensions to t
37、hree significant figures in unitsof millimeters inches.11.2.3 Select pins with the largest diameters that will easilyfit into the honeycomb cells.11.2.4 Place the pins in cell rows in the top and bottomportions of the specimen. Fig. 1 shows a fixture that has beensatisfactorily used to hold and load
38、 the pins.11.3 Speed of TestingSet the speed of testing so as toproduce failure within 3 to 6 min. If the ultimate strength of thematerial cannot be reasonably estimated, initial trials should beconducted using standard speeds until the ultimate strength ofthe material and the compliance of the syst
39、em are known, andspeed of testing can be adjusted. The suggested standard headdisplacement rate is 25 mm/min 1 in./min.11.4 Test EnvironmentIf possible, test the specimen underthe same fluid exposure level used for conditioning. However,cases such as elevated temperature testing of a moist specimenp
40、lace unrealistic requirements on the capabilities of commontesting machine environmental chambers. In such cases, themechanical test environment may need to be modified, forexample, by testing at elevated temperature with no fluidexposure control, but with a specified limit on time to failurefrom wi
41、thdrawal from the conditioning chamber. Record anymodifications to the test environment.11.5 Specimen InstallationInstall the specimen/fixture as-sembly into the test machine test fixture.11.6 LoadingApply a tensile force to the specimen at thespecified rate while recording data. Load the specimen u
42、ntil thespecimen is completely torn into two pieces or an unacceptablefailure mode occurs.11.7 Data RecordingRecord force versus head displace-ment data continuously, or at frequent intervals. For this testmethod, a sampling rate of 3 to 10 data recordings per secondand a target minimum of 300 data
43、points per test are recom-mended. Record the maximum force.11.8 Failure ModesFailure of the honeycomb at the load-ing pin location is not an acceptable failure mode and the datashall be noted as invalid. Node bond failure is considered to bethe only acceptable failure mode.12. Validation12.1 Values
44、for ultimate properties shall not be calculatedfor any specimen that breaks at some obvious flaw, unless suchflaw constitutes a variable being studied. Retests shall beperformed for any specimen on which values are not calcu-lated.12.2 Asignificant fraction of failures in a sample populationoccurrin
45、g at the pin locations shall be cause to reexamine themeans of force introduction into the material. Factors consid-ered should include the fixture alignment, specimen surfacecharacteristics, and uneven machining of specimen ends.13. Calculation13.1 Tensile-Node Bond StrengthCalculate the tensilenod
46、e bond strength of the core material as follows: 5Pbt(1)13.2 StatisticsFor each series of tests calculate the aver-age value, standard deviation, and coefficient of variation (inpercent) for tensile-node bond strength:x 5S(i51nXiD/n (2)Sn215 S(i51nxi22 nx2D/n 2 1! (3)C363/C363M 09 (2015)3CV 5 100 3S
47、n21/x (4)where:x = sample mean (average),Sn1= sample standard deviation,CV = sample coefficient of variation (in percent),n = number of specimens, andx1= measured or derived property.14. Report14.1 Report the following information, or references point-ing to other documentation containing this infor
48、mation, to themaximum extent applicable (reporting of items beyond thecontrol of a given testing laboratory, such as might occur withmaterial details or panel fabrication parameters, shall be theresponsibility of the requestor):NOTE 4Guides E1309, E1434 and E1471 contain data reportingrecommendation
49、s for composite materials and composite materials me-chanical testing.14.1.1 The revision level or date of issue of this test method,14.1.2 The name(s) of the test operator(s),14.1.3 Any variations to this test method, anomalies noticedduring testing, or equipment problems occurring during testing,14.1.4 Results of any nondestructive evaluation tests,14.1.5 Method of preparing the test specimen, includingspecimen labeling scheme and method, specimen geometry,sampling method, and specimen cutting method,
