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  • 简介:Factorsinfluencingbondingstrengthoflaminatedbamboostripslumber(LBSL)wereinvestigatedinthispaper.Inordertofindanoptimizedtechnology,thispaperinvestigatedhowthethicknessofbamboostrips,theassemblyorientationofbamboocurtain,thetypeofadhesives,aswellascouplingagenttreatmentofbamboocurtainaffectedthebondingstrength.Thefollowingconclusionsweredrawn:1)Thethinnerthethicknessofthebamboostrips,thebiggerthebondingstrengthofLBSL;2)Theassemblyor...

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  • 简介:Structuralfinger-jointed(FJ)lumberwasusedmainlyinstructuralapplicationsincludingglue-laminatedbeamsandwoodenI-joistsandmorerecentlyinparallelchordwoodtrusses.ThepaperevaluatedstrengthpropertiesofstructuralFJlumberbythreenondestructivemethods(edge-wisebending,longitudinalandtransversalvibration)inordertofindanalternativetotraditionalevaluationmethods.LumberwassawnfromthelogsfollowingapatterntypicallyusedinChinatomaximizethevolumeofrecover...

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  • 简介:Theadditionofahardenerisnecessaryforthecuringofurea-formaldehyde(UF)adhesivesintheproductionofMDFandparticleboard.Themostcommonlyusedhardener,ammoniumchloride,however,issuspectedtocausetheformationofpoisonousdioxinwhenwasteboardsarecombustedandhenceconsideredasapotentialsourceofpollution.Toassessthefeasibilityofsubstitutingammoniumsulphateforammoniumchloride,workingpropertiesandbondingstrengthweremeasuredforUFadhesiveswiththetwo...

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  • 简介:Resonanceflexuralvibration(FastFourierTransform,FFT),ultrasonicwave(Pundit)andstresswave(Metriguard)techniqueswereexaminedasmeansofevaluatingthestaticmodulusofelasticity(MOE)andpredictingthemodulusofrupture(MOR)offinger-jointedlumberspecimensmadewithfourkindsofEucalyptus(Eucalyptus.citriodora,E.exserta,E.grandisxE.urophyllaandE.grandis).DynamicMOEwascalculatedfromfrequencyandtimeobtainedfromforcedvibrationsandsoundsinducedinthefourspeciesoffinger-jointedspecimens.ItwasfoundthatcorrelationcoefficientsbetweendensityandstaticMOEanddynamicMOEwerestatisticallysignificantatthe0.01level.AnditwasalsofoundthatthethreenondestructivetechniquescanproviderapidandaccuratemeanstodeterminetheMOE,andthedynamicMOEwasmoreaccuratetopredictstaticMOEthandensity.ButthecorrelationcoefficientbetweendynamicMOE,staticMOEandMORwerelowerthanresultsreportedbyotherresearchersforsolidwood,andwerenotstatisticallysignificant.ItcanbeconcludedthatthethreenondestructivetechniquesareusefulforevaluatingtheMOE,butnotsuitableforpredictingtheMORoffinger-jointed.

  • 标签: 非破坏性评估 强度性能 成材森林 林业建设