STD 3100橡胶剪切模量的判定.doc

STANDARDSTD 3100Utgva/IssueSida/Page24Bestmning av skjuvmodul. Gummi.Determination of shear modulus. Rubber. 橡胶剪切模量的判定ProvningsmetodTesting methodOrienteringIntroductionDenna standard avser bestmning av skjuvmodul (kvadrupelmetoden) och verensstmmer i ska med ISO 1827-1976.This standard refers to determination of the shear modulus (guadruple shear method) and essentially agrees with ISO 1827-1976.1Provkropp1Test specimenStandardprovkroppen bestr av fyra identiska gummielement: tjocklek 4 0,1 mm, bredd 20 0,1 mm och lngd 25 0,1 mm. De fastvulkas mellan styva stlplattor, tjocklek 5 + 0, -0,1 mm enligt figur 1. Tre provkroppar anvnds fr varje prov.The standard test psecimen consists of four identical rubber elements: thickness 4 0,1 mm, width 20 0,1 mm and length 25 0,1 mm. They are bonded to stiff sheet metal plates, thickness 5 + 0, -0,1 mm as per fig 1. Three test pieces are used for each test.1.1Tillverkning1.1ManufacturingStlplattorna behandlas p normalt stt med bindemedel. Ovulkat gummimaterial utstansas tillrckligt stort s att skgg erhlls vid vulkningen.The sheet metal plates are treated in the usual way with a bonding agent. Unvulcanized rubber material is punched big enough for flash to be achieved when vulcanized.Denna utfrs antingen genom formpressning av den sammansatta provkroppen, eller genom sprutpressning.This is either made through compression moulding of the composite test specimen or through transfer moulding.Vulkningen sker vid lmplig temperatur under bestmd tid.The vulcanization is carried out at an adequate temperature for a fixed time.Vid uttag av provkropp ur formen fr provkroppen ej utsttas fr ondig dragpknning.When taking the test specimen out of the form it must not be exposed to any unnecessary tensile stress.2Konditionering2ConditioningProvkropparna ska efter framstllning frvaras minst 16 timmar och max 4 mnader i normal laboratorieatmosfr innan provning sker.The test specimens must be kept in normal laboratory conditions for min. 16 hours and max. 4 months before testing.3Provning3TestingProvkroppen faststts i en dragprovmaskin och utstts fr minst fem dragningar i fljd till samma distans som berknat prov fr att reducera Mullineffekten. Drefter nollstlls kraftmtaren medan provkroppen r utsatt fr en svag dragkraft, exempelvis 10 N.The test specimen is fixed in a tensile test apparatus and is exposed to at least 5 pulls in a row to the same distnace as for a calculated test to reduce the Mullin-effect. Then the strength indicator is set to zero while the test specimen is exposed to a slight traction force, e.g. 10 N.Dragning utfrs sedan med en hastighet av 25 5 mm/min till nskad skjuvning.Pulling is then carried out at a rate of 25 5 mm/min till the shear required is obtained.4Berkning och angivande av resultat4Calculation and reporting of resultsSkjuvspnningen uttryckt i Pascal (1 Pa = 1 N/m2) berknas genom att dividera plagd kraft med bunden yta (2x20x25x10-6 m2).Shear stress expressed in Pascal (1 Pa = 1 N/m2) is calculated through division of the force put on by the bonded area (2x20x25x10-6 m2).Skjuvtjningen berknas genom att dividera halva den aktuella deformationen av provkroppen med gummielementens tjocklek, 8 mm (samma lngdenhet).The shear strain is calculated through division of half the deformation in question of the test sepcimen by the sheared thickness of the rubber part, 8 mm (the same length unit).Skjuvmodulen r kvoten mellan skjuvspnning och skjuvtjning.The shear modulus is equal to the quotient between shear stress and shear strain.I provningsrapporten anges skjuvspnningen i kPa.The shear stress is stated in kPa in the test report.5Rapport5ReportProvningsrapport ska innehlla uppgift om:The test report shall include information about:a.materialbeteckning och -ursprunga. material designation and its originb.betingelser vid cess stipulations of the test piecesc.tillverknings och provningsdatumc.manufacturing and testing datesd.konditionerings- och provningsklimatd.conditioning and testing climatee.resultat och kommentarere.results and commentsf.avvikelser frn standardenf.divergences from standardndringar