JY 25-1988 三相感应电动机模型
作者:标准资料网 时间:2024-05-02 19:09:33 浏览:8600
来源:标准资料网
基本信息
| 标准名称： | 三相感应电动机模型 |
| 中标分类： |
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| 替代情况： | JY 25-1979 |
| 发布日期： | |
| 实施日期： | 2002-05-01 |
| 首发日期： | |
| 作废日期： | |
| 出版日期： | |
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所属分类： 轻工 文化与生活用品 文教 体育 娱乐用品 办公用品及办公机具
【英文标准名称】:StandardTestMethodsforBendTestingofMaterialforDuctility
【原文标准名称】:材料延展性的弯曲测试的标准试验方法
【标准号】:ASTME290-1997a(2004)
【标准状态】:现行
【国别】:
【发布日期】:1997
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E28.02
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:弯曲试验;试验;机械试验;材料;延展性;金属
【英文主题词】:bend;crack;ductility;flattenedbend;forminglimit;fracture;freebend;guidedbend;mandrel;pin;plunger;roller
【摘要】:Bendtestsforductilityprovideasimplewaytoevaluatethequalityofmaterialsbytheirabilitytoresistcrackingorothersurfaceirregularitiesduringonecontinuousbend.Noreversalofthebendforceshallbeemployedwhenconductingthesetests.Thetypeofbendtestuseddeterminesthelocationoftheforcesandconstraintsonthebentportionofthespecimen,rangingfromnodirectcontacttocontinuouscontact.Thetestcanterminateatagivenangleofbendoveraspecifiedradiusorcontinueuntilthespecimenlegsareincontact.Thebendanglecanbemeasuredwhilethespecimenisunderthebendingforce(usuallywhenthesemi-guidedbendtestisemployed),orafterremovaloftheforceaswhenperformingafree-bendtest.Productrequirementsforthematerialbeingtesteddeterminethemethodused.Materialswithanas-fabricatedcrosssectionofrectangular,round,hexagonal,orsimilardefinedshapecanbetestedinfullsectiontoevaluatetheirbendpropertiesbyusingtheproceduresoutlinedinthesetestmethods,inwhichcaserelativewidthandthicknessrequirementsdonotapply.1.1Thesetestmethodscoverbendtestingforductilityofmaterials.Includedintheproceduresarefourconditionsofconstraintonthebentportionofthespecimen;aguided-bendtestusingamandrelorplungerofdefineddimensionstoforcethemid-lengthofthespecimenbetweentwosupportsseparatedbyadefinedspace;asemi-guided-bendtestinwhichthespecimenisbent,whileincontactwithamandrel,throughaspecifiedangleortoaspecifiedinsideradius(r)ofcurvature,measuredwhileunderthebendingforce;afree-bendtestinwhichtheendsofthespecimenarebroughttowardeachother,butinwhichnotransverseforceisappliedtothebenditselfandthereisnocontactoftheconcaveinsidesurfaceofthebendwithothermaterial;abendandflattentest,inwhichatransverseforceisappliedtothebendsuchthatthelegsmakecontactwitheachotheroverthelengthofthespecimen.1.2Afterbending,theconvexsurfaceofthebendisexaminedforevidenceofacrackorsurfaceirregularity.Ifthespecimenfractures,thematerialhasfailedthetest.Whencompletefracturedoesnotoccur,thecriterionforfailureisthenumberandsizeofcracksorothersurfaceirregularityvisibletotheunaidedeyeoccurringontheconvexsurfaceofthespecimenafterbending,asspecifiedbytheproductstandard.Anycrackswithinonethicknessoftheedgeofthespecimenarenotconsideredabendtestfailure.Cracksoccurringinthecornersofthebentportionshallnotbeconsideredsignificantunlesstheyexceedthesizespecifiedforcornercracksintheproductstandard.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Inch-poundvaluesgiveninparentheseswereusedinestablishingtestparametersandareforinformationonly.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:H23
【国际标准分类号】:77_040_10(MECHANICALTESTINGOFMETALS)
【页数】:7P.;A4
【正文语种】:
