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时间:2018-10-31
《外文翻译---频率和锚固长度对超声波在锚杆中传播行为的影响》由会员上传分享,免费在线阅读,更多相关内容在应用文档-天天文库。
1、英文原文EffectsoffrequencyandgroutedlengthonthebehaviorofguidedultrasonicwavesinrockboltsD.H.Zoua,Y.Cui,V.Madengaa,C.ZhangAbstractExperimentswereconductedtostudythebehaviorofguidedwavesinfreeandgroutedrockbolts.Ultrasonicwaveswithfrequenciesfrom25to100kHzwereusedasexcitationinputs.Tes
2、tswerefirstconductedonfreeboltstohelpunderstandthebehaviorofguidedwavesinnon-groutedbolts.Theeffectsofwavefrequencyandgroutedlengthonthegroupvelocityandattenuationoftheguidedultrasonicwaveswerethenevaluated.Thetestresultsindicatedclearbutdifferenttrendsforthegroupvelocityinthefreea
3、ndthegroutedbolts.Theattenuationinfreeboltswasnotaffectedbyboltlengthandfrequency.However,ingroutedboltsitincreasedwithfrequencyandgroutedlength.Itwasalsofoundthatthetwomainsourcesofattenuationarethesetupenergyloss,whichhasafixedquantityforaspecifictypeoftestsetup,andthedispersivean
4、dspreadingenergylosswhichvarieswithfrequencyandboltlength.2007ElsevierLtd.Allrightsreserved.Keywords:Rockbolts;Guidedwaves;Attenuation;Amplitude;Groupvelocity1.IntroductionRockboltsarewidelyusedinundergroundandsurfaceexcavationsinminingandcivilengineeringforgroundreinforcementands
5、tabilization.Inmanyapplications,rockboltsaregroutedinthegroundwithcementorresin.Testingofthegroutqualityandmonitoringofthebolttensionofrockboltshaslongbeenachallengeinthefield.Conventionally,groutqualityisassessedbypull-outtestandover-coring.Bothmethodsaredestructiveandtimeconsumin
6、g.Theusefulnessofpull-outtestresultsasameasureofthegroutqualitycanbelimitedbythecriticallengthofgroutbeyondwhichthesteelboltwillfailfirst.Therefore,othermethods,suchasnon-destructivetestingmethodsusingultrasonicwaveshavebecomeattractive.Inrecentyears,researchinthisareahasbeenveryac
7、tive.Itisnoticedthatpropertiesofguidedwaves,suchasvelocityandattenuation,arefunctionsoftheinputwavefrequency.Althoughtheguidedultrasonicwaveseemstobeapromisingmethodformonitoringrockbolts,researchinthisareaisstillintheearlystageandmanytechnicalproblemsremaintobesolved.Inagroutedbo
8、lt,wavebehaviorisnotonlyrelatedto
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