1、Designation: C 363/C 363M 09Standard Test Method forNode Tensile Strength of Honeycomb Core Materials1This standard is issued under the fixed designation C 363/C 363M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of las
2、t 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 The values st
3、ated 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.1.3
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 and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Docum
5、ents2.1 ASTM Standards:2C 274 Terminology of Structural Sandwich ConstructionsD 883 Terminology Relating to PlasticsD 3878 Terminology for Composite MaterialsD 5229/D 5229M Test Method for Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-trix Composite MaterialsE4 Practices f
6、or Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical Test-ingE 122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE 177 Practice for Use of the Terms Precision and Bias inASTM Test Met
7、hodsE 456 Terminology Relating to Quality and StatisticsE 1309 Guide for Identification of Fiber-ReinforcedPolymer-Matrix Composite Materials in DatabasesE 1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in DatabasesE 1471 Guide for Identification of Fibers, Fil
8、lers, and CoreMaterials in Computerized Material Property Databases3. Terminology3.1 DefinitionsTerminology D 3878 defines terms relatingto high-modulus fibers and their composites. TerminologyC 274 defines terms relating to structural sandwich construc-tions. Terminology D 883 defines terms relatin
9、g to plastics.Terminology E6defines terms relating to mechanical testing.Terminology E 456 and Practice E 177 define terms relating tostatistics. In the event of a conflict between terms, TerminologyD 3878 shall have precedence over the other Terminologies.3.2 Symbols:3.2.1 stensile node strength, M
10、Pa psi.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 x sample 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
11、.4. Summary 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
12、only acceptable 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
13、 bond strength is a funda-mental property than can be used in determining whetherhoneycomb cores can be handled during cutting, machiningand forming without the nodes breaking. The tensile-nodebond strength is the tensile stress that causes failure of the1This test method is under the jurisdiction o
14、f ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich Construction.Current edition approved April 1, 2009. Published May 2009. Originallyapproved in 1955. Last previous edition approved in 2000 as C 363 00.2For referenced ASTM standards, visit
15、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
16、, United States.honeycomb 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 development.6. Interferences6
17、.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 GeometrySpecific geometric facto
18、rs 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 environmen-tal conditions under which the tests are conducted. Specimenstested in various environments ca
19、n 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 inaccordance with Practices E4and shall satisfy the followingrequirements:7.1.1 Testing Machine Configuration
20、The 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 movable head shall be capable o
21、f 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 shallindicate the force wi
22、th 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 the instruments shall be suita
23、ble for reading to within1%ofthe sample width and thickness. For typical specimen geom-etries, an instrument with an accuracy of 625 m 60.001 in.is desirable for both thickness and width measurements.8. Sampling and Test Specimens8.1 SamplingThe number of test specimens and themethod of their select
24、ion 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 portionof the material which ap
25、pears to have a maximum of distortedcells or misalignment of bond areas. For statistically significantdata, consult the procedures outlined in Practice E 122. Reportthe method of sampling.8.2 GeometryThe test specimens shall be 130 6 5mm56 0.2 in. wide. The test specimens shall have a minimumlength
26、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 testmethod provided the a
27、ctual 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 allowable test programs.8.3 Speci
28、men 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 the nodebond areas.8.4 Lab
29、elingLabel 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.FIG. 1 Honeycomb Core Tensile-Node Bond Strength Test SetupC 363/C 363M 0929. Calibration9.1 The accuracy of all measuring eq
30、uipment 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 D 5229/D 5229M; however, if the test re-questor doe
31、s not explicitly specify a pre-test conditioningenvironment, no conditioning is required and the test speci-mens may be tested as prepared.10.2 The pre-test specimen conditioning process, to includespecified environmental exposure levels and resulting moisturecontent, shall be reported with the test
32、 data.NOTE 2The term “moisture,” as used in Test Method D 5229/D 5229M, 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 process shall be reported as
33、“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 3Determine specific material pr
34、operty, 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 environmental conditioning tes
35、t 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 final specimen machining
36、and any condi-tioning, but before testing, measure the specimen length andwidth. The accuracy of these measurements shall be within 0.5% of the dimension. Measure the specimen thickness; theaccuracy of this measurement shall be within 625 m 60.001in.). Record the dimensions to three significant figu
37、res 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 the pins.11.3 Speed
38、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 system are known, andspee
39、d 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 specimenplace unrealistic requ
40、irements 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 withdrawal from the con
41、ditioning 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 until thespecimen is c
42、ompletely 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 points per test are r
43、ecom-mended. Record the maximum force.11.8 Failure ModesFailure of the honeycomb at theloading pin location is not an acceptable failure mode and thedata shall be noted as invalid. Node bond failure is consideredto be the only acceptable failure mode.12. Validation12.1 Values for ultimate properties
44、 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 populationoccurring at the pin locations
45、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 tensilenode bond strength of the
46、core material as follows:s5Pbt(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 5 (i 5 1nXi!/n (2)Sn215(i 5 1nxi22 nx2!/n 2 1! (3)CV 5 100 3 Sn21/x (4)where:x = sample mean (average),
47、Sn1= sample standard deviation,CV = sample coefficient of variation (in percent),n = number of specimens, andC 363/C 363M 093x1= measured or derived property.14. Report14.1 Report the following information, or references point-ing to other documentation containing this information, to themaximum ext
48、ent 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 E 1309, E 1434 and E 1471 contain data reportingrecommendations for composite materi
49、als 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,14.1.6 Calibration dates an
