【英文标准名称】:CompactingofConcretebyVibrating;CompactingbySurfaceVibrators
【原文标准名称】:采用振荡法压实混凝土.第5部分:用表面振荡器压实
【标准号】:DIN4235-5-1978
【标准状态】:现行
【国别】:德国
【发布日期】:1978-12
【实施或试行日期】:
【发布单位】:德国标准化学会(DIN)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:压实;定义;混凝土
【英文主题词】:compacting;definitions;concrete;concretes
【摘要】:Compactingconcretebyvibrating;compactingbysurfacevibratorsSerragedubétonparVibration;serrageparvibrateurssuperficielsDieseNormwurdevomFachbereichVIIBeton-undStahlbetonbau/DeutscherAusschu?fürStahlbetondesNormenaus-schussesBa
【中国标准分类号】:Q13;P97
【国际标准分类号】:91_100_30;91_080_40
【页数】:2P;A4
【正文语种】:德语
【英文标准名称】:StandardPracticeforDeterminingResidualStressesinExtrudedorMoldedSulfonePlastic(SP)PartsbyImmersioninVariousChemicalReagents
【原文标准名称】:通过浸入各种化学试剂中测定挤压或模铸砜塑料件中残余应力的标准实施规程
【标准号】:ASTMD7474-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【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】:D20.15
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:liquidreagent;PESU;PPSU;PSU;residualstress;SP;stresscracking
【摘要】:Thermoplasticmoldingscontainresidualstressesduetodifferentialcoolingratesthroughthethicknessofthemolding.Changesinresidualstresshavebeenfoundtooccurwithtimeaftermoldingduetostressrelaxation.Manypartperformanceparametersaswellaspartfailuresareaffectedbythelevelofresidualstresspresentinapart.Residualstressescauseshrinkage,warpage,andadecreaseinenvironmentalstresscrackresistance.Thispracticeestimatestherelativemagnitudeofresidualstressesinpartsproducedfromtheseriesofsulfoneplastics(SP),namelypolysulfone(PSU),polyethersulfone(PESU),andpolyphenylsulfone(PPSU)materials.Nodirectcorrelationhasbeenestablishedbetweentheresultsofthedeterminationofresidualstressesbythispracticeandpartperformanceproperties.Forthisreason,thispracticeisnotrecommendedasasubstituteforothertests,norisitintendedforuseinpurchasingspecificationsforparts.Despitethislimitation,thispracticedoesyieldinformationofvalueinindicatingthepresenceofresidualstressesandtherelativequalityofplasticparts.Residualstressescannotbeeasilycalculated,henceitisimportanttohaveanexperimentalmethod,suchasthispractice,toestimateresidualstresses.ThispracticeisusefulforextrudersandmolderswhowishtoevaluateresidualstressesinSPparts.Thiscanbeaccomplishedbyvisualexaminationafterimmersioninoneormorechemicalreagentstoevaluatewhetherornotcrackingoccurs.Stresseswillrelaxaftermoldingorextrusion.Accordingly,bothimmersioninthetestmediumandvisualexaminationmustbemadeatidenticaltimesandconditionsafterprocessing,ifcomparingparts.Itisimportanttonotethedifferencesinparthistory.Thus,thistechniquemaybeusedasanindicationforqualityofplasticprocessing.Thepracticeisusefulprimarilyforindicatingresidualstressesnearthesurface.1.1ThispracticecoverstheevaluationofresidualstressesinextrudedprofileormoldedSPparts.Thepresenceandrelativemagnitudeofresidualstressesareindicatedbythecrazingofthespecimenpartuponimmersioninoneormoreofaseriesofchemicalreagents.ThespecifiedchemicalreagentswerepreviouslycalibratedbyuseofEnvironmentalStressCracking(ESC)techniquestocausecrazinginsulfoneplastics(SP)atspecifiedstresslevels.1.2Thispracticeappliesonlytounfilledinjectionmoldingandextrusiongradematerialsofhighmolecularweightasindicatedbythefollowingmeltflowrates:PSU9g/10min,max.,PESU30g/10m,max,andPPSU25g/10min,max.Lowermolecularweight(highermeltflow)materialswillcrazeatlowerstresslevelsthanindicatedinTables1-3.(SeeSpecificationD6394formeltflowrateconditions.)1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.Note18212;ThereisnoequivalentISOstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:G31
【国际标准分类号】:83_080_01
【页数】:4P.;A4
【正文语种】:英语
基本信息
| 标准名称： | 冷镦六角头螺栓 细杆凹模 B型 |
| 中标分类： |
机械 >>
工艺装备 >>
模具 |
| 替代情况： | 被JB/T 4209.6-96代替 |
| 发布日期： | |
| 实施日期： | 1999-06-04 |
| 首发日期： | |
| 作废日期： | |
| 出版日期： | |
| 页数： | 2页 |
适用范围
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前言
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引用标准
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所属分类： 机械 工艺装备 模具