1、Designation: C 481 99 (Reapproved 2005)Standard Test Method forLaboratory Aging of Sandwich Constructions1This standard is issued under the fixed designation C 481; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 This test method covers the determination
3、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 i
4、n SI units are to be regarded as thestandard. The inch-pound units given may be approximate.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 pract
5、ices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 273 Test Method for Shear Properties in Sandwich CoreMaterialsC 297/C 297M Test Method for Flatwise Tensile Strengthof Sandwich ConstructionsC 363 Test Method for Delamination St
6、rength of Honey-comb Core MaterialsC 364 Test Method for Edgewise Compressive Strength ofSandwich ConstructionsC 365 Test Methods for Flatwise Compressive Properties ofSandwich CoresC 393 Test Method of Flexural Properties of SandwichConstructionsD 1781 Test Method for Climbing Drum Peel forAdhesive
7、s3. 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 These test methods provide a standard method ofobtaining simulated environmenta
8、l 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. Apparatus4.1 Water tank, steam sprayer, oven, and freezer, all capableof maintaining
9、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 2.6. Aging Test Procedures6.1 Subject each specimen to six complete cycles of l
10、abo-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) for 1 h.6.2.2 Spray with steam and water vapor at 95 6 3C (200 65F) for 3 h.6.2.3
11、 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 Cycle B:6.3.1 Totally immerse the specimen horizontally in water at50 6 3C (12
12、0 6 5F) for 1 h.6.3.2 Heat in dry air at 70 6 3C (160 6 5F) for 3 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 Mar. 1, 2005. Published March 2005. O
13、riginallyapproved in 1961. Last previous edition approved in 1999 as C 481 99.2For referenced ASTM standards, 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 on
14、the ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3.3 Spray with hot water at 70 6 3F (160 6 5F) for 3 h.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
15、 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 shall be sprayed so as to contact all panelsurfaces.6.5 After completion of the six cycles of exposure, furtherco
16、ndition 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 constant weight.7. Procedure7.1 Make frequent inspections of the material during theaging cycles for any signs
17、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 Test specimens of the material is received and afteraging, in accordance with procedures selected from the foll
18、ow-ing:Shear Test Test Method C 273Compressive Strength Test Methods C 364 and C 365Delamination Strength Test Method C 363Tension Test Test Method C 297/C 297MFlatwise Flexure Test Test Method C 393Climbing Drum Peel Test Method D 17818. Calculations8.1 After the tests following the laboratory agin
19、g 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 Calculate the degradation percentages from Eq 1.Degradation Percentage 5conditioned test valueas received tes
20、t value3 100 (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 orientation,9.1.3 Number of specimens tested,9.1.4 The cycle (A or B) the specimens were subjected,9.1.5 The “as
21、 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 Precision It is not possible to specify the precision ofthe procedure in Test Method C 481 for conducting sandwichconstruction laborat
22、ory 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 testmethod, bias has not been determined.11. Keywords11.1 aging; degradation; sandwich; sandwich constructionAST
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26、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 reprints (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).C 481 99 (2005)2
