typically

振动噪声常用名词术语解释

振动:Theoscillatory(backandforth)motionofaphysicalobject.

噪声:Anycomponentofatransducersignalwhichdoesnotreprent

thevariableintendedtobemeasured.

固有频率(振动中最重要的概念):Thefrequencyoffreevibrationofa

mechanicalsystematwhichaspecificnaturalmodeofthesystem

elementsassumesitsmaximumamplitude.

强迫振动:Theresponvibrationofamechanicalsystemduetoa

forcingfunction(excitingforce).Typically,forcedvibrationhasthe

samefrequencyasthatoftheexcitingforce.

自由振动:Vibrationresponofamechanicalsystemfollowingan

impul-likeinitialperturbation(changeofposition,velocityor

externalforce).Dependingonthekindofperturbation,themechanical

systemrespondswithfreevibrationsatoneormoreofitsnatural

frequencies.

绝对振动:Vibrationofanobjectasmeasuredrelativetoaninertial

(fixed)rometersandvelocitytransducersmeasure

absolutevibrationtypicallyofmachinehousingsorstructures;thus

theyarereferredtoasismictransducersorinertialtransducers.

简谐振动:Sinusoidalvibrationwithasinglefrequencycomponent.

赫兹:(Hz)Unitoffrequencymeasurementincyclespercond.

频率:Therepetitionrateofaperiodicvibrationperunitoftime.

Vibrationfrequencyistypicallyexpresdinunitsofcyclesper

cond(Hertz)orcyclesperminute(tomoreeasilyrelatetoshaft

rotativespeedfrequency).Infact,sincemanycommonmachine

malfunctionsproducevibrationwhichhasafixedrelationshiptoshaft

rotativespeed,vibrationfrequencyisoftenexpresdasafunctionof

shaftrotativespeed.1Xisavibrationwithafrequencyequaltoshaft

rpm,2Xvibrationisattwiceshaftrpm,0.5Xvibrationwitha

frequencyequaltoone-halfshaftrpm,etc.

振幅:Themagnitudeofperiodicdynamicmotion(vibration).

Amplitudeistypicallyexpresdintermsofsignallevel,e.g.,millivo

ltsormilliamps,ortheengineeringunitsofthemeasuredvariable,

e.g.,mils,micrometres(fordisplacement),inchespercond(for

velocity),litudeofasignalcanbemeasuredintermsof

peaktopeak,zerotopeak,rootmeansquare,oraverage.

相位角:Thetimingrelationship,indegrees,betweentwovibration

signals,suchasaKeyphasor?pulandavibrationsignal;also,the

phadifferencebetweentwosignals,suchastheinputforcesignaland

"lag"correspondsto"minus"inmathematical

formulations.

加速度:monicmotion,

lunitsforaccelerationare

feetpercondpercond(ft/s2)pk,meterspercondpercond

(m/s2)pk,ormorecommonlygpk(=accelerationofearthsgravity=

386.1in/s2=32.17ft/s2=9.81m/s2).Accelerationmeasurementsare

generallymadewithanaccelerometerandaretypicallyudto

evaluatehighfrequencyvibrationofamachinecasingorbearinghousing

duetobladepassing,gearmesh,cavitation,rollingelementbearing

defects,etc.

速度:lunitsfor

velocityareinches/condormillimetres/cond,ty

measurementsareudtoevaluatemachinehousingandotherstructural

onicintegrationofavelocitysignal

yieldsdisplacement,butnotposition.

位移:Thechangeindistanceorpositionofanobjectrelativetoa

eryvibrationdisplacementistypicallyapeaktopeak

measurementoftheobrvedvibrationalmotionorposition,andis

ityprobes

integrationisrequiredtoconvert

avelocitysignaltodisplacement,butdoesnotprovidetheinitial

displacement(distancefromareference)measurement.

分贝:Anumericalexpressionoftheratioofthepowerorvoltage

levelsofelectricalsignals.

dB=10logP1/P2=20logV1/V2.

共振:Theconditioninwhichthefrequencyofanexternalforce

coincideswithanaturalfrequencyof

ancetypicallyisidentifiedbyanamplitude

peak,accompaniedbyamaximumrateofchangeofphalagangle.

频谱:Commonlyaprentationoftheamplitudesofasignal's

requencycontent

ofasignal.

信噪比:Thenumberformedbydividingthemagnitudeofthesignalby

isignalhas

ahighSignal-to-NoiRatio,whileahighnoisignalhasalow

canoriginatefrommanydifferent

sourcesandisconsideredtobeanypartofthesignalwhichdoesnot

reprenttheparameterbeingmeasured.

比例阻尼:proportionaldamping

传递矩阵法:transfermatrixmethod

颤振:flutter喘振:surge

功率谱密度函数:powerspectraldensityfunction

功率谱密度矩阵:powerspectraldensitymatrix

互谱密度函数:cross-spectraldensityfunction

互谱密度函数:cross-spectraldensitymatrix

互相关函数:cross-correlationfunction

混沌振动:chaoticvibration

简正模态函数:normalmodalfunction

简正模态矩阵:normalmodalmatrix

模态截断法:modetruncationmethod

模态综合法:componentmodalsynthesismethod

均值Meanvalue

方差Variance

机械阻抗Mechanicalimpedance

位移阻抗Displacementimpedance

速度阻抗Speedimpedance

加速度阻抗Accelerationimpedance