1、Designation: C363/C363M 16Standard 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, the year of last re
2、vision. 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 stated
3、 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 This
4、 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 Documents
5、2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for MoistureAbsorption Prop-erties and Equilibrium Conditioning of Polymer MatrixComposite MaterialsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relatin
6、g 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 Statistics3. Terminol
7、ogy3.1 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. Terminology E456 and PracticeE177
8、 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:3.2.1 tensile node strength, MPa psi.3.2.2 Pultimate tensile force, N lb.3.2.3 binitial width of specimen, mm in.3.2.4 tthickness of specim
9、en, 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. Summary of Test Method4.1 This test method consists of subjecting a honeycombconstruction to a uniaxial te
10、nsile 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 acceptable failure mode for tensile-node bondstrength is the tensile failure of the node-to-node honeycom
11、bbond 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 strength is a funda-mental property than can be used in determining whetherhoneycomb cores can be handle
12、d during cutting, machiningand forming without the nodes breaking. The tensile-nodebond strength is the 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 tensi
13、le-node bond strength data for quality control, accep-tance specification testing, and research and development.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 appr
14、oved April 1, 2016. Published April 2016. Originallyapproved in 1955. Last previous edition approved in 2015 as C363 09(2015). DOI:10.1520/C0363_C0363M-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM
15、Standards 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 States16. Interferences6.1 System AlignmentExcessive bending will cause pre-mature failure. Every e
16、ffort 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 factors that affect thetensile-node bond strength include cell geometry, cell si
17、ze, cellwall thickness and, specimen dimensions (length, width andthickness).6.3 EnvironmentResults are affected by the environmentalconditions under which the tests are conducted. Specimenstested in various environments can exhibit significant differ-ences in both strength behavior and failure mode
18、. 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 Testing Machine ConfigurationThe testing machineshall have both an essentially stationary head and a mo
19、vablehead.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 of beingregulated in accordance with 11.3.7.1.3 Force IndicatorThe testing
20、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 with an accuracy over the force range(s) ofinterest of within 61 % of the in
21、dicated 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 suitable for reading to within1%ofthe sample width and thickness. For typical
22、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 and themethod of their selection depend on the purpose of theparticular test under consideration, and n
23、o 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 appears to have a maximum of distortedcells or misalignment of bond areas. F
24、or 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 shall have a minimumlength of 260 10 in. with a minimum test section outside thegrips of 200 mm 8 in.
25、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 actual thickness value is reported. Non-standard thickness specimens shall h
26、ave 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 Specimen Preparation and MachiningSpecimensshall be cut such that the number of
27、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 LabelingLabel the test specimens so that they will bedistinct from each other
28、and traceable back to the panel oforigin, and will neither influence the test nor be affected by it.9. Calibration9.1 The accuracy of all measuring equipment shall havecertified calibrations that are current at the time of the use ofthe equipment.FIG. 1 Honeycomb Core Tensile-Node Bond Strength Test
29、 SetupC363/C363M 16210. Conditioning10.1 The recommended pre-test condition is effective mois-ture equilibrium at a specific relative humidity as establishedby Test Method D5229/D5229M; however, if the test requestordoes not explicitly specify a pre-test conditioning environment,no conditioning is r
30、equired 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 be reported with the test data.NOTE 2The term “moisture,” as used in Test Method D5229/D5229M, includes not
31、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 “uncondi-tioned” and the moisture content as “unknown.”11. Procedure11.1 Parameters t
32、o 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 property, accuracy, and datareporting requirements prior to test for proper selection o
33、f 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 test parameters.11.1.4 If performed, sampling method, specimen geometry,and test paramet
34、ers 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 and anyconditioning, but before testing, measure the specimen lengthand width. The ac
35、curacy 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 three significant figures in unitsof millimeters inches.11.2.3 Select pins with the largest diameters that wi
36、ll 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 of TestingSet the speed of testing so as toproduce failure within 3 to 6 min. If the ul
37、timate 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, andspeed of testing can be adjusted. The suggested standard headdisplacement rate is 25 mm/min
38、 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 requirements on the capabilities of commontesting machine environmental chambers. In such c
39、ases, 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 conditioning chamber. Record anymodifications to the test environment.11.5 Specimen Instal
40、lationInstall 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 completely torn into two pieces or an unacceptablefailure mode occurs.11.7 Data Recordin
41、gRecord 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 recom-mended. Record the maximum force.11.8 Failure ModesFailure of the honeycomb at the
42、 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 for ultimate properties shall not be calculatedfor any specimen that breaks at some obvious flaw, unless suc
43、hflaw 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 shall be cause to reexamine themeans of force introduction into the material. Factors
44、 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 core material as follows: 5Pbt(1)13.2 StatisticsFor each series of tests calculate th
45、e 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)CV 5 100 3Sn21/x (4)where:x = sample mean (average),Sn1= sample standard deviation,CV = sample coefficient of variation (in percent),n = num
46、ber of specimens, andx1= measured or derived property.C363/C363M 16314. Report14.1 Report the following information, or references point-ing to other documentation containing this information, to themaximum extent applicable (reporting of items beyond thecontrol of a given testing laboratory, such a
47、s might occur withmaterial details or panel fabrication parameters, shall be theresponsibility of the requestor):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 eq
48、uipment 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 and methods for all meas
49、urementsand test equipment,14.1.7 Details of loading pins and apparatus, includingdimensions and material used.14.1.8 Type of test machine, alignment results, and dataacquisition sampling rate and equipment type,14.1.9 Measured length and width and thickness for eachspecimen (prior to and after conditioning, if appropriate),14.1.10 Description of core material; cell size, density, andtype,14.1.11 Any special treatment of core before test such asboiling water, and so forth,14.1.12 Conditioning parameters
