1、Designation: C366/C366M 11Standard Test Methods forMeasurement of Thickness of Sandwich Cores1This standard is issued under the fixed designation C366/C366M; 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover plant manufacturing proce
3、-dures for measuring the thickness of flat sandwich cores.Permissible core material forms include those with continuousbonding surfaces (such as balsa wood and foams) as well asthose with discontinuous bonding surfaces (such as honey-comb). The two test methods covered include the following:1.1.1 Te
4、st Method ARoller-Type Thickness Tester.1.1.2 Test Method BDisk-Type Thickness Tester.NOTE 1These test methods are designed for measuring thickness ofcore as it is produced and are not intended for use in determiningdimensions of core specimens for other tests.1.2 The values stated in either SI unit
5、s 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.1.2.1 Within the text the
6、inch-pound units 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 li
7、mitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C274 Terminology of Structural Sandwich ConstructionsD883 Terminology Relating to PlasticsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-t
8、rix Composite MaterialsE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE171 Specification for Atmospheres for Conditioning andTesting Flexible Barrier MaterialsE177 Practice for Use of the Terms Precision and Bias inA
9、STM Test 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 Fib
10、ers, Fillers, 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 re
11、lating to plastics.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 CVcoefficient of variation statistic of a samplepopulation for a given property (i
12、n percent)3.2.2 Sn-1standard deviation statistic of a sample popula-tion for a given property3.2.3 Xitest result for an individual specimen from thesample population for a given property3.2.4 xmean or average (estimate of mean) of a samplepopulation for a given property4. Summary of Test Methods4.1
13、These test methods consist of environmentally condi-tioning a sandwich core specimen, zeroing a thickness tester,placing the core underneath the tester, and measuring the corethickness by sliding the core underneath the tester. Procedures1These test methods are under the jurisdiction of ASTM Committ
14、ee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich Construction.Current edition approved April 1, 2011. Published May 2011. Originallyapproved in 1955. Last previous edition approved in 2005 as C366 05. DOI:10.1520/C0366_C0366M-11.2For referenced ASTM sta
15、ndards, visit 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,
16、 PA 19428-2959, United States.are provided for thickness measurement using both roller-typeand disk-type thickness testers.5. Significance and Use5.1 Normally, a close tolerance is desirable for core thick-ness so that sandwich panels may be manufactured with all thesandwich components fitting prope
17、rly and without crushing thecore.5.2 These test methods are designed for measuring thick-ness of core as it is produced and are not intended for use indetermining dimensions of core specimens for other tests.5.3 These test methods provide standard methods of obtain-ing the core thickness of flat san
18、dwich core materials, andprovide a basis for determining average thickness dimensions.The thickness properties derived may be used in designproperties, material specifications, research and developmentapplications, and quality assurance.5.4 Factors that influence core thickness measurement andshall
19、therefore be reported include the following: core materialthrough-thickness rigidity, surface roughness, specimen geom-etry (including warpage), specimen preparation, methods ofdimensional measurement, specimen conditioning, and mois-ture content during dimensional measurements.6. Interferences6.1 M
20、aterial and Specimen PreparationPoor materialfabrication practices and damage induced by improper speci-men machining are known causes of high data scatter incomposites and sandwich structures in general. Importantaspects of sandwich core specimen preparation that contributeto data scatter include t
21、he existence of joints, voids or othercore discontinuities, out-of-plane curvature/warpage, and sur-face roughness.6.2 Measurement Equipment and ProceduresResults areaffected by the method of thickness measurement, use ofpressure to flatten warped core, and the distance along whichthickness is measu
22、red.6.3 EnvironmentResults are affected by the environmen-tal conditions under which specimens are conditioned, as wellas the conditions under which the tests are conducted. Speci-mens tested in various environments, with different ambientmoisture contents, can exhibit significant differences in mea
23、-sured thickness.7. Apparatus7.1 Test Method ARoller-Type Thickness Tester:7.1.1 Roller-Type Thickness TesterThe tester shall consistof a flat table with a rigid yoke framework attached, as shownin Fig. 1. Two rollers shall be mounted on this yoke, one fixedin position and one movable in the vertica
24、l direction. Thevertical movement of the upper roller shall be translated to adial gage, calibrated in 0.01 mm 0.001 in. increments, thatregisters the amount of variation above or below a presetnominal dimension. The lower roller shall be fixed in positionso that it projects 6 mm 0.25 in. above the
25、measurementsurface. The upper roller shall exert a force of 18 N 4 lbf onthe core material.7.2 Method BDisk-Type Thickness Tester:7.2.1 Disk-Type Thickness TesterThe tester shall consistof a flat table with a rigid yoke framework attached, as shownin Fig. 2. A 25 mm 1 in. diameter presser disk movab
26、le in avertical direction shall be mounted on the yoke. The verticalmovement of the disk shall be translated to a dial gage,calibrated in 0.01 mm 0.001 in. increments, that registers theamount of variation above or below a preset nominal dimen-sion. The disk shall exert a force of 24 N 5.5 lbf on th
27、e corematerial.7.3 Measurement SurfaceA flat, rigid surface shall bepositioned such that the specimen can be supported underneaththe thickness tester without bending or warping.8. Sampling and Test Specimens8.1 SamplingTest at least five specimens per test condi-tion, or take five readings from alte
28、rnative locations on a singlelarge specimen, unless valid results can be gained through theuse of fewer specimens, as in the case of a designed experi-ment. For statistically significant data, consult the proceduresoutlined in Practice E122. Report the method of sampling.8.2 GeometryTest specimens s
29、hall be flat but otherwisemay be any length, width, and thickness consistent with thelimits of the measuring apparatus.FIG. 1 Roller-Type Thickness TesterC366/C366M 1128.3 Specimen Preparation and MachiningEnsure the testspecimens are flat, and that the facing plane surfaces areparallel to each othe
30、r. Take precautions when cutting speci-mens to avoid notches, undercuts, and rough or unevensurfaces which can affect the measured thickness due toinappropriate machining methods. Record and report the speci-men cutting preparation method.8.4 LabelingLabel the test specimens so that they will bedist
31、inct from each other and traceable back to the sheet 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 use of theequipment.10. Conditioning10.1 As the physical
32、 dimensions of the core materials areaffected by moisture, it is recommended to subject the testspecimens to standard ASTM atmospheric conditions (Speci-fication E171)of236 3C 73 6 5F and 50 6 5 % relativehumidity, in accordance with Procedure C of Test MethodD5229/D5229M. However, if the test reque
33、stor does notexplicitly specify a pre-test conditioning environment, noconditioning is required and the test specimens may be testedas prepared.10.2 The pre-test specimen conditioning process, to includespecified environmental exposure parameters, shall be reportedwith the test data.10.3 If no expli
34、cit conditioning process is performed, thespecimen conditioning process shall be reported as “uncondi-tioned”.10.4 Record the actual temperature and humidity at the timeof measurement.11. Procedure11.1 Parameters to be Specified Before Test:11.1.1 The specimen sampling method, specimen geometry,and
35、conditioning travelers (if required).11.1.2 The properties and data reporting format desired.NOTE 2Determine specific material property, accuracy, and datareporting requirements prior to test for proper selection of apparatus.11.1.3 The environmental conditioning test parameters.11.1.4 The method of
36、 thickness measurement (Method A orB) and accuracy of thickness tester.11.2 General Instructions:11.2.1 Report any deviations from this test method, whetherintentional or inadvertent.11.2.2 Condition the specimens as required. Store the speci-mens in the conditioned environment until test time, if t
37、he testenvironment is different than the conditioning environment.11.3 Method ARoller-Type Thickness Tester:11.3.1 Place a gage block of a thickness equal to the desirednominal core thickness between the rollers on the measurementsurface, and zero the dial gage.11.3.2 Remove the gage block and inser
38、t the core materialto be measured.11.3.3 Move the core through the rollers back and forth andobserve the dial gage readings. Record the maximum variationin readings on the dial gage to three significant figures in unitsof millimetres inches (with an accuracy of 625 m 60.001in.), plus and minus, alon
39、g with the distance traversed underthe rollers. Take care not to exert hand pressure on the corenear the rollers, as this will affect the dial gage readings.FIG. 2 Disk-Type Thickness TesterC366/C366M 11311.4 Method BDisk-Type Thickness Tester:11.4.1 Place a gage block of a thickness equal to the de
40、sirednominal core thickness on the measurement surface beneaththe disk and zero the dial gage.11.4.2 Remove the gage block and insert the core materialto be measured.11.4.3 With the disk automatically reciprocating vertically,move the core in a saw tooth pattern along the length of thespecimen and o
41、bserve the dial gage readings. Record themaximum variation in readings on the dial gage to threesignificant figures in units of millimetres inches (with anaccuracy of 625 m 60.001 in.), plus and minus, along withthe distance traversed under the disk.11.4.4 If the specimen is excessively warped and t
42、he weightof the presser disk is not sufficient to straighten it, use anadditional adjustable pressure ring concentric with the 25 mm1 in. diameter disk presser foot to force the specimen to lieflat on the measurement surface. The outside diameter of thisring shall be 115 mm 4.5 in.12. Validation12.1
43、 Property values shall not be calculated for any speci-men that contains some obvious flaw described in 6.1, unlesssuch flaw constitutes a variable being studied. Retests shall beperformed for any specimen on which values are not calcu-lated.13. Calculation13.1 StatisticsFor each series of tests cal
44、culate the aver-age value, standard deviation, and coefficient of variation (inpercent) for the maximum variation in dial gage readings, bothplus and minus:x5 (i51nxi!/n (1)Sn215(i51nxi22 nx2!/n 2 1! (2)CV 5 100 3 Sn21/x(3)where:x= sample mean (average),Sn-1= sample standard deviation,CV = sample co
45、efficient of variation, %,n = number of specimens, andxi= measured or derived property.14. 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
46、 laboratory, such as might occur withmaterial details or panel fabrication parameters, shall be theresponsibility of the requestor):NOTE 3Guides E1309, E1434 and E1471 contain data reportingrecommendations for composite materials and composite materials test-ing.14.1.1 The revision level or date of
47、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 Identification of all the materials constituent to thesandwich core specimen tested, including for ea
48、ch: materialspecification, material type, manufacturers material designa-tion, manufacturers batch or lot number, source (if not frommanufacturer), date of certification, and expiration of certifi-cation.14.1.5 Description of the fabrication steps used to preparethe sandwich core including: fabricat
49、ion start date, fabricationend date, process specification, and a description of theequipment used.14.1.6 Method of preparing the test specimen, includingspecimen labeling scheme and method, specimen geometry,sampling method, and specimen cutting method.14.1.7 Results of any nondestructive evaluation tests.14.1.8 Calibration dates and methods for all measurementsand test equipment.14.1.9 Type of thickness tester and method used (Method Aor B).14.1.10 If Method A is utilized, roller dimensions (diameterand length) u
