【英文标准名称】:Metallicmaterials-Methodoftestforthedeterminationofresistancetostablecrackextensionusingspecimensoflowconstraint
【原文标准名称】:金属材料.测定低限制条件下使用的样品抗稳定裂纹扩张的试验方法
【标准号】:ISO22889-2007
【标准状态】:现行
【国别】:国际
【发布日期】:2007-12
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC164
【标准类型】:()
【标准水平】:()
【中文主题词】:抗裂纹扩张;抗裂纹;定义;材料试验;材料;材料测试;机械试验;金属的;金属材料;金属;抗破裂构造;测试
【英文主题词】:Crack-extension-resistance;Crackingresistance;Definitions;Materialtests;Materials;Materialstesting;Mechanicaltesting;Metallic;Metallicmaterials;Metals;Resistancetocrackformation;Testing
【摘要】:ThisInternationalStandardspecifiesmethodsfordeterminingtheresistancetostablecrackextensionintermsofcrackopeningdisplacement,δ5,andcriticalcracktipopeningangle,ψc,forhomogeneousmetallicmaterialsbythequasistaticloadingofcrackedspecimensthatexhibitlowconstrainttoplasticdeformation.Compactandmiddle-crackedtensionspecimensarenotched,precrackedbyfatigue,andtestedunderslowlyincreasingdisplacement.ThisInternationalStandarddescribesmethodscoveringtestsonspecimensnotsatisfyingrequirementsforsize-insensitivefractureproperties;namely,compactspecimensandmiddle-crackedtensionspecimensinrelativelythingauges.Methodsaregivenfordeterminingthecrackextensionresistancecurve(R-curve).PointvaluesoffracturetoughnessforcompactspecimensaredeterminedaccordingtoISO12135.Methodsfordeterminingpointvaluesoffracturetoughnessforthemiddle-crackedtensionspecimenaregiveninAnnexD.Crackextensionresistanceisdeterminedusingeitherthemultiple-specimenorsingle-specimenmethod.Themultiple-specimenmethodrequiresthateachofseveralnominallyidenticalspecimensbeloadedtoaspecifiedlevelofdisplacement.Theextentofductilecrackextensionismarkedandthespecimensarethenbrokenopentoallowmeasurementofcrackextension.Single-specimenmethodsbasedoneitherunloadingcomplianceorpotentialdroptechniquescanbeusedtomeasurecrackextension,providedtheymeetspecifiedaccuracyrequirements.Recommendationsforsingle-specimentechniquesaredescribedinISO12135.Usingeithertechnique,theobjectiveistodetermineasufficientnumberofdatapointstoadequatelydescribethecrackextensionresistancebehaviourofamaterial.Themeasurementofδ5isrelativelysimpleandwellestablished.Theδ5resultsareexpressedintermsofaresistancecurve,whichhasbeenshowntobeuniquewithinspecifiedlimitsofcrackextension.Beyondthoselimits,δ5R-curvesforcompactspecimensshowastrongspecimendependencyonspecimenwidth,whereastheδ5R-curvesformiddle-crackedtensionspecimensshowaweakdependency.CTOAismoredifficulttodetermineexperimentally.ThecriticalCTOAisexpressedintermsofaconstantvalueachievedafteracertainamountofcrackextension.TheCTOAconcepthasbeenshowntoapplytoverylargeamountsofcrackextensionandcanbeappliedbeyondthecurrentlimitsofδ5applications.Bothmeasuresofcrackextensionresistancearesuitableforstructuralassessment.Theδ5conceptiswellestablishedandcanbeappliedtostructuralintegrityproblemsbymeansofsimplecrackdrivingforceformulaefromexistingassessmentprocedures.TheCTOAconceptisgenerallymoreaccurate.Itsstructuralapplicationrequiresnumericalmethods,i.e.finiteelementanalysis.InvestigationshaveshownaverycloserelationbetweentheconceptofconstantCTOAandauniqueR-curveforbothcompactandmiddle-crackedtensionspecimensuptomaximumload.Furtherstudyisrequiredtoestablishanalyticalornumericalrelationshipsbetweentheδ5R-curveandthecriticalCTOAvalues.
【中国标准分类号】:H22
【国际标准分类号】:77_040_10
【页数】:49P.;A4
【正文语种】:英语


【英文标准名称】:TwistDrills
【原文标准名称】:麻花钻
【标准号】:ANSI/ASMEB94.11M-1993
【标准状态】:作废
【国别】:美国
【发布日期】:1993
【实施或试行日期】:
【发布单位】:美国国家标准学会(ANSI)
【起草单位】:ANSI
【标准类型】:()
【标准水平】:()
【中文主题词】:麻花钻;丝锥;尺寸
【英文主题词】:Classificationsystems;Cuttingtools;Definition;Definitions;Diameter;Dimensions;Drills;Marking;Metric;Screw-cuttingtools;Taps(threading);Tolerances(measurement);Twistdrills
【摘要】:
【中国标准分类号】:J41
【国际标准分类号】:25_100_30
【页数】:
【正文语种】:英语