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【英文标准名称】:StandardPracticeforEstablishingAllowablePropertiesforVisually-GradedDimensionLumberfromIn-GradeTestsofFull-SizeSpecimens
【原文标准名称】:来自于全尺寸试样的分级试验的目视尺寸分级的木材的容许性能的确定用标准试验方法
【标准号】:ASTMD1990-2007
【标准状态】:现行
【国别】:
【发布日期】:2007
【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】:D07.02
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:测试;木材
【英文主题词】:
【摘要】:1.1Duetothenumberofspecimensinvolvedandthenumberofmechanicalpropertiestobeevaluated,amethodologyforevaluatingthedataandassigningallowablepropertiestobothtestedanduntestedgrade/sizecellsisnecessary.SamplingandanalysisoftestedcellsarecoveredinPracticeD2915.ThemechanicaltestmethodsarecoveredinTestMethodsD198andD4761.ThispracticecoversthenecessaryproceduresforassigningallowablestressandmodulusofelasticityvaluestodimensionlumberfromIn-Gradetests.Thepracticeincludesmethodstopermitassignmentofallowablestressandmodulusofelasticityvaluestountestedsizesandgrades,aswellassomeuntestedproperties.1.2Abasicassumptionoftheproceduresusedinthispracticeisthatthesamplesselectedandtestedarerepresentativeoftheentireglobalpopulationbeingevaluated.Thisapproachisconsistentwiththehistoricalclearwoodmethodologyofassigninganallowablepropertytovisually-gradedlumberwhichwasrepresentativeoftheentiregrowthrangeofaspeciesorspeciesgroup.Everyeffortshallbemadetoensurethetestsampleisrepresentativeofpopulationbygradeandsize(see7.1.1and7.1.2).1.3Thispracticecoverstheprinciplesandproceduresforestablishingallowablestressvaluesforbending,tensionparalleltograin,compressionparalleltograinandmodulusofelasticityvaluesforstructuraldesignfrom"In-Grade"testsoffull-sizevisuallygradedsolidsawndimensionlumber.Thispracticeisfocusedon,butisnotlimitedto,gradeswhichusedtheconceptsincorporatedinPracticeD245andweredevelopedandinterpretedunderAmericanSoftwoodLumberPS20-70.Note1-IntheimplementationoftheNorthAmericanIn-Gradetestprogram,allowablestressvaluesforcompressionperpendiculartograinandshearparalleltograinforstructuraldesignwerecalculatedusingtheproceduresofPracticeD245.1.4Thispracticeonlycoversdimensionlumber.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:B69
【国际标准分类号】:79_040
【页数】:29P.;A4
【正文语种】: