资源描述：
《机械专业外文文献翻译3.docx》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。
1、英文原文APracticalApproachtoVibrationDetectionandMeasurementPhysicalPrinciplesandDetectionTechniquesBy:JohnWilson,theDynamicConsultant,LLCThistutorialaddressesthephysicsofvibration;dynamicsofaspringmasssystem;damping;displacement,velocity,andacceleration;andtheoperatingprinciplesofthesensorsthatd
2、etectandmeasuretheseproperties・Vibrationisoscillatorymotionresultingfromtheapplicationofoscillatoryorvaryingforcestoastructure.Oscillatorymotionreversesdirection.Asweshallsee,theoscillationmaybecontinuousduringsometimeperiodofinterestoritmaybeintermittent.Itmaybeperiodicornonperiodic,i.e.5itm
3、ayormaynotexhibitaregularperiodofrepetition.Thenatureoftheoscillationdependsonthenatureoftheforcedrivingitandonthestructurebeinedriven.Motionisavectorquantity,exhibitingadirectionaswellasamagnitude.Thedirectionofvibrationisusuallydescribedintermsofsomearbitrarycoordinatesystem(typicallyCartes
4、ianororthogonal)whosedirectionsarecalledaxes・Theoriginfortheorthogonalcoordinatesystemofaxesisarbitrarilydefinedatsomeconvenientlocation.Mostvibratoryresponsesofstructurescanbemodeledassingle-degree-of-freeclomspringmasssystems,andmanyvibrationsensorsuseaspringmasssystemasthemechanicalpartoft
5、heirtransductionmechanism・Inadditiontophysicaldimensions,aspringmasssystemcanbecharacterizedbythestiffnessofthespring,K,andthemass,M,orweight,W,ofthemass.Thesecharacteristicsdeterminenotonlythestaticbehavior(staticdeflection,d)ofthestructure,butalsoitsdynamiccharacteristics.Ifgistheaccelerati
6、onofgravity:F=MAW=MgK=F/d=W/dd=F/K=W/K=Mg/KDynamicsofaSpringMassSystemThedynamicsofaspringmasssystemcanbeexpressedbythesystem'sbehaviorinfreevibrationand/orinforcedvibration.FreeVibration.Freevibrationisthecasewherethespringisdeflectedandthenreleasedandallowedtovibratefreely.Examplesincludead
7、ivingboard,abungeejumper,andapendulumorswingdeflectedandlefttofreelyoscillate・Twocharacteristicbehaviorsshouldbenoted.First,dampinginthesystemcausestheamplitudeoftheoscillationstodecreaseovertime.Thegreaterthedamping,thefastertheamplitudedecr
