1、Designation: C481 99 (Reapproved 2016)Standard Test Method forLaboratory Aging of Sandwich Constructions1This standard is issued under the fixed designation C481; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript 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 This test method covers the determinatio
3、n of the resis-tance of sandwich panels to severe exposure conditions asmeasured by the change in selected properties of the materialafter exposure. The exposure cycle to which the specimen issubjected is an arbitrary test having no correlation with naturalweathering conditions.1.2 The values stated
4、 in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.2.1 ExceptionThe inch-pound units are provided forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
5、y 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 Documents2.1 ASTM Standards:2C273 Test Method for Shear Properties of Sandwich CoreMaterialsC297/C297M Test Method for Flatwise T
6、ensile Strength ofSandwich ConstructionsC363 Test Method for Delamination Strength of HoneycombCore MaterialsC364 Test Method for Edgewise Compressive Strength ofSandwich ConstructionsC365/C365M Test Method for Flatwise Compressive Prop-erties of Sandwich CoresC393 Test Method for Flexural Propertie
7、s of SandwichConstructionsD1781 Test Method for Climbing Drum Peel for Adhesives3. Significance and Use3.1 Most sandwich panels are subjected to various tempera-ture and humidity environments. This laboratory aging testdetermines the selected panel property degradation undersimulated conditions.3.2
8、These test methods provide a standard method ofobtaining simulated environmental degradation data for qualitycontrol, acceptance specification testing, and research anddevelopment; however, these laboratory aging test proceduresdo not have any correlation with natural weathering conditions.4. Appara
9、tus4.1 Water tank, steam sprayer, oven, and freezer, all capableof maintaining the required environment.4.2 Test apparatus, shall conform to the appropriate ASTMTest Method listed in Section 2.5. Test Specimens5.1 The test specimens shall conform to the appropriateASTM Test Method listed in Section
10、2.6. Aging Test Procedures6.1 Subject each specimen to six complete cycles of labo-ratory aging, using either Cycle A (more severe) or Cycle B(milder). The time interval between cycles shall not exceed 30min.6.2 Cycle A:6.2.1 Totally immerse the specimen horizontally in water at50 6 2C (120 6 3F) fo
11、r 1 h.6.2.2 Spray with steam and water vapor at 95 6 3C (200 65F) for 3 h.6.2.3 Store at 12 6 3C (10 6 5F) for 20 h.6.2.4 Heat at 100 6 2C (210 6 3F) in dry air for 3 h.6.2.5 Spray again with steam and water vapor at 95 6 3C(200 6 5F) for 3 h.6.2.6 Heat in dry air at 100 6 2C (210 6 3F) for 18 h.6.3
12、 Cycle B:6.3.1 Totally immerse the specimen horizontally in water at50 6 3C (120 6 5F) for 1 h.1This specification is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.09 onSandwich Construction.Current edition approved Sept. 15,
13、2016. Published October 2016. Originallyapproved in 1961. Last previous edition approved in 2011 as C481 99 (2011).DOI: 10.1520/C0481-99R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volum
14、e 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 States16.3.2 Heat in dry air at 70 6 3C (160 6 5F) for 3 h.6.3.3 Spray with hot water at 70 6 3C (160 6 5F) for 3h
15、.6.3.4 Heat in dry air at 70 6 3C (160 6 5F) for 18 h.6.4 Test Conditions:6.4.1 Steam shall be diffused so as to contact both faces andall edges of panel.6.4.2 The maximum relative humidity of the air shall be10 %; air shall be circulated by means of a fan to heat allsurfaces uniformly.6.4.3 Water s
16、hall be sprayed so as to contact all panelsurfaces.6.5 After completion of the six cycles of exposure, furthercondition the specimen at a temperature of 23 6 3C (73 65F) and a relative humidity of 50 6 5 % and bring it back toconstant weight (61 %) before testing. Report the time re-quired to attain
17、 constant weight.7. Procedure7.1 Make frequent inspections of the material during theaging cycles for any signs of delamination or other disintegra-tion. If there is any apparent damage to the material, describeit in the report as well as the stage of the cycle in which thedamage became apparent.7.2
18、 Test specimens of the material is received and afteraging, in accordance with procedures selected from the follow-ing:Shear Test Test Method C273Compressive Strength Test Methods C364 and C365/C365MDelamination Strength Test Method C363Tension Test Test Method C297/C297MFlatwise Flexure Test Test M
19、ethod C393Climbing Drum Peel Test Method D17818. Calculations8.1 After the tests following the laboratory aging treatmentare completed, calculate the results as specified in the appro-priate method and compare them with the corresponding valuesobtained from the tests made on material as received.8.2
20、 Calculate the degradation percentages from Eq 1.Degradation Percentage 5conditioned test valueas received test value3100 (1)9. Report9.1 The report shall include the following:9.1.1 Description of the test specimens as required by thetest method used,9.1.2 Dimensions of the test specimens, core ori
21、entation,9.1.3 Number of specimens tested,9.1.4 The cycle (A or B) the specimens were subjected,9.1.5 The “as received” test results,9.1.6 The “conditioned” test results, and9.1.7 The specimen degradation percentage; individual val-ues and average.10. Precision and Bias10.1 PrecisionIt is not possib
22、le to specify the precision ofthe procedure in Test Method C481 for conducting sandwichconstruction laboratory aging because of the unavailability ofconsistent samples for testing.10.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedures in this testm
23、ethod, bias has not been determined.11. Keywords11.1 aging; degradation; sandwich; sandwich constructionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that
24、determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapprove
25、d or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel
26、 that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual repri
27、nts (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 99 (2016)2
