1、Designation: C366/C366M 11C366/C366M 16Standard 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
2、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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods cover plant m
3、anufacturing procedures for measuring the thickness of flat sandwich cores. Permissiblecore material forms include those with continuous bonding surfaces (such as balsa wood and foams) as well as those withdiscontinuous bonding surfaces (such as honeycomb). The two test methods covered include the f
4、ollowing:1.1.1 Test Method ARoller-Type Thickness Tester.1.1.2 Test Method BDisk-Type Thickness Tester.NOTE 1These test methods are designed for measuring thickness of core as it is produced and are not intended for use in determining dimensionsof core specimens for other tests.1.2 The values stated
5、 in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.2.1
6、 Within the text the inch-pound units are shown in brackets.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabi
7、lity of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C274 Terminology of Structural Sandwich Constructions (Withdrawn 2016)3D883 Terminology Relating to PlasticsD3878 Terminology for Composite MaterialsD5229/D5229M Test Method for Moisture Absorption Properties and E
8、quilibrium Conditioning of Polymer Matrix CompositeMaterialsE122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot orProcessE171 Practice for Conditioning and Testing Flexible Barrier PackagingE177 Practice for Use of the Terms Prec
9、ision and Bias in ASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE1309 Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in Databases (Withdrawn 2015)3E1434 Guide for Recording Mechanical Test Data of Fiber-Reinforced Composite Materials in Database
10、s (Withdrawn 2015)3E1471 Guide for Identification of Fibers, Fillers, and Core Materials in Computerized Material Property Databases (Withdrawn2015)33. Terminology3.1 DefinitionsTerminology D3878 defines terms relating to high-modulus fibers and their composites.Terminologycomposites, as C274 define
11、swell as terms relating to structural sandwich constructions. Terminology D883 defines1 These test methods are under the jurisdiction of ASTM Committee D30 on Composite Materials and is the direct responsibility of Subcommittee D30.09 on SandwichConstruction.Current edition approved April 1, 2011Mar
12、ch 15, 2016. Published May 2011March 2016. Originally approved in 1955. Last previous edition approved in 20052011 asC366 05.C366 11. DOI: 10.1520/C0366_C0366M-11.10.1520/C0366_C0366M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceas
13、tm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becau
14、seit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Ba
15、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1terms relating to plastics. Terminology E456 and Practice E177 define terms relating to statistics. In the event of a conflict betweenterms, Terminology D3878 shall have precedence over the other terminologies.3.2 Symbols:
16、3.2.1 CVcoefficient of variation statistic of a sample population for a given property (in percent)3.2.2 Sn-1standard deviation statistic of a sample population for a given property3.2.3 Xitest result for an individual specimen from the sample population for a given property3.2.4 xmean or average (e
17、stimate of mean) of a sample population for a given property4. Summary of Test Methods4.1 These test methods consist of environmentally conditioning a sandwich core specimen, zeroing a thickness tester, placingthe core underneath the tester, and measuring the core thickness by sliding the core under
18、neath the tester. Procedures are providedfor thickness measurement using both roller-type and disk-type thickness testers.5. Significance and Use5.1 Normally, a close tolerance is desirable for core thickness so that sandwich panels may be manufactured with all thesandwich components fitting properl
19、y and without crushing the core.5.2 These test methods are designed for measuring thickness of core as it is produced and are not intended for use in determiningdimensions of core specimens for other tests.5.3 These test methods provide standard methods of obtaining the core thickness of flat sandwi
20、ch core materials, and providea basis for determining average thickness dimensions. The thickness properties derived may be used in design properties, materialspecifications, research and development applications, and quality assurance.5.4 Factors that influence core thickness measurement and shall
21、therefore be reported include the following: core materialthrough-thickness rigidity, surface roughness, specimen geometry (including warpage), specimen preparation, methods ofdimensional measurement, specimen conditioning, and moisture content during dimensional measurements.6. Interferences6.1 Mat
22、erial and Specimen PreparationPoor material fabrication practices and damage induced by improper specimenmachining are known causes of high data scatter in composites and sandwich structures in general. Important aspects of sandwichcore specimen preparation that contribute to data scatter include th
23、e existence of joints, voids or other core discontinuities,out-of-plane curvature/warpage, and surface roughness.6.2 Measurement Equipment and ProceduresResults are affected by the method of thickness measurement, use of pressure toflatten warped core, and the distance along which thickness is measu
24、red.6.3 EnvironmentResults are affected by the environmental conditions under which specimens are conditioned, as well as theconditions under which the tests are conducted. Specimens tested in various environments, with different ambient moisturecontents, can exhibit significant differences in measu
25、red thickness.7. Apparatus7.1 Test Method ARoller-Type Thickness Tester:7.1.1 Roller-Type Thickness TesterThe tester shall consist of a flat table with a rigid yoke framework attached, as shown inFig. 1. Two rollers shall be mounted on this yoke, one fixed in position and one movable in the vertical
26、 direction. The verticalmovement of the upper roller 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 dimension. The lower roller shall be fixed in position so that it projects 6mm 0.25 in. above the
27、 measurement surface. The upper roller shall exert a force of 18 N 4 lbf on the core material.C366/C366M 1627.2 Method BDisk-Type Thickness Tester:7.2.1 Disk-Type Thickness TesterThe tester shall consist of a flat table with a rigid yoke framework attached, as shown in Fig.2. A 25 mm 1 in. diameter
28、presser disk movable in a vertical direction shall be mounted on the yoke. The vertical movement ofthe disk shall be translated to a dial gage, calibrated in 0.01 mm 0.001 in. increments, that registers the amount of variation aboveor below a preset nominal dimension. The disk shall exert a force of
29、 24 N 5.5 lbf on the core material.7.3 Measurement SurfaceA flat, rigid surface shall be positioned such that the specimen can be supported underneath thethickness tester without bending or warping.8. Sampling and Test Specimens8.1 SamplingTest at least five specimens per test condition, or take fiv
30、e readings from alternative locations on a single largespecimen, unless valid results can be gained through the use of fewer specimens, as in the case of a designed experiment. Forstatistically significant data, consult the procedures outlined in Practice E122. Report the method of sampling.8.2 Geom
31、etryTest specimens shall be flat but otherwise may be any length, width, and thickness consistent with the limits ofthe measuring apparatus.8.3 Specimen Preparation and MachiningEnsure the test specimens are flat, and that the facing plane surfaces are parallel toeach other. Take precautions when cu
32、tting specimens to avoid notches, undercuts, and rough or uneven surfaces which can affectthe measured thickness due to inappropriate machining methods. Record and report the specimen cutting preparation method.8.4 LabelingLabel the test specimens so that they will be distinct from each other and tr
33、aceable back to the sheet of origin,and will neither influence the test nor be affected by it.9. Calibration9.1 The accuracy of all measuring equipment shall have certified calibrations that are current at the time of use of the equipment.FIG. 1 Roller-Type Thickness TesterC366/C366M 16310. Conditio
34、ning10.1 As the physical dimensions of the core materials are affected by moisture, it is recommended to subject the test specimensto standard ASTM atmospheric conditions (Specification E171) of 23 6 3C 73 6 5F and 50 6 5 % relative humidity, inaccordance with Procedure C of Test Method D5229/D5229M
35、. However, if the test requestor does not explicitly specify a pre-testconditioning environment, no conditioning is required and the test specimens may be tested as prepared.10.2 The pre-test specimen conditioning process, to include specified environmental exposure parameters, shall be reported wit
36、hthe test data.10.3 If no explicit conditioning process is performed, the specimen conditioning process shall be reported as “unconditioned”.10.4 Record the actual temperature and humidity at the time of measurement.FIG. 2 Disk-Type Thickness TesterC366/C366M 16411. Procedure11.1 Parameters to be Sp
37、ecified 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 2Determine specific material property, accuracy, and data reporting requirements prior to test for proper selection of app
38、aratus.11.1.3 The environmental conditioning test parameters.11.1.4 The method of thickness measurement (Method A or B) and accuracy of thickness tester.11.2 General Instructions:11.2.1 Report any deviations from this test method, whether intentional or inadvertent.11.2.2 Condition the specimens as
39、required. Store the specimens in the conditioned environment until test time, if the 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 desired nominal core thickness between the rollers on th
40、e measurementsurface, and zero the dial gage.11.3.2 Remove the gage block and insert the core material to be measured.11.3.3 Move the core through the rollers back and forth and observe the dial gage readings. Record the maximum variation inreadings on the dial gage to three significant figures in u
41、nits of millimetres inches (with an accuracy of 625 m 60.001 in.),plus and minus, along with the distance traversed under the rollers. Take care not to exert hand pressure on the core near the rollers,as this will affect the dial gage readings.C366/C366M 16511.4 Method BDisk-Type Thickness Tester:11
42、.4.1 Place a gage block of a thickness equal to the desired nominal core thickness on the measurement surface beneath thedisk and zero the dial gage.11.4.2 Remove the gage block and insert the core material to be measured.11.4.3 With the disk automatically reciprocating vertically, move the core in
43、a saw tooth pattern along the length of the specimenand observe the dial gage readings. Record the maximum variation in readings on the dial gage to three significant figures in unitsof millimetres inches (with an accuracy of 625 m 60.001 in.), plus and minus, along with the distance traversed under
44、 thedisk.11.4.4 If the specimen is excessively warped and the weight of the presser disk is not sufficient to straighten it, use an additionaladjustable pressure ring concentric with the 25 mm 1 in. diameter disk presser foot to force the specimen to lie flat on themeasurement surface. The outside d
45、iameter of this ring shall be 115 mm 4.5 in.12. Validation12.1 Property values shall not be calculated for any specimen that contains some obvious flaw described in 6.1, unless such flawconstitutes a variable being studied. Retests shall be performed for any specimen on which values are not calculat
46、ed.13. Calculation13.1 StatisticsFor each series of tests calculate the average value, standard deviation, and coefficient of variation (in percent)for the maximum variation in dial gage readings, both plus and minus:xH 5S(i51nxiD/n (1)Sn215S(i51nxi22n xH2D/n 21! (2)CV51003Sn21/xH (3)where:x = sampl
47、e mean (average),Sn-1 = sample standard deviation,CV = sample coefficient of variation, %,n = number of specimens, andxi = measured or derived property.14. Report14.1 Report the following information, or references pointing to other documentation containing this information, to themaximum extent app
48、licable (reporting of items beyond the control of a given testing laboratory, such as might occur with materialdetails or panel fabrication parameters, shall be the responsibility of the requestor):NOTE 3Guides E1309, E1434 and E1471 contain data reporting recommendations for composite materials and
49、 composite materials 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 noticed during testing, or equipment problems occurring during testing.14.1.4 Identification of all the materials constituent to the sandwich core specimen tested, including for each: materialspecification, material type, manufacturers material designation, manufacturers batch or lot number, source (if not frommanufacturer), da
