振动台选择原理.ppt

《振动台选择原理.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、VibrationBasicsandShakerSelection9/3/20211DeterminingShakerSizingProperShakerselectionrequiresapplicationofNewton’sSecondLawofMotion:Force=MassxAcceleration(F=MA)Vibrationsystemshaveoutputforcesratingsdefinedintermsof:Sineforce:lbs(kN)peakRandomforce:lbs(kN)rmsShockforce:l

2、bs(kN)peak9/3/20212SuitabilityofaSpecificTestSystemcanbeevaluatedintermsofthefollowing:ForceRequirement(lbf)UUT+Fixture+ArmaturexG=Fx1.30=DesiredForceShakerSystemMaximumDisplacementDeterminedbytestenvironmentMaximumVelocityDeterminedbytestenvironmentApplyingNewton’sLawInSha

3、kerSelection9/3/20213Themassvalue(M)intheinitialformulaofF=MAmustincludeallmovingmassesattachedtotheshakerarmaturesurfaceincludingthearmaturemassitself:shakerarmature+headexpanderorslipplatewithitsdriverbar+testspecimen+specimeninterfacefixture,includingboltsandbearingstict

4、ionifthesystemisdrivingahorizontalplateusinghydrostaticbearings.F=maDeterminingMovingMASS9/3/20214DeterminingandEvaluatingMassTestArticles,SlipTables,HeadExpandersandFixturesSize,MassandFrequencyResponseOverturningMoment/GuidanceIssues(UUT+Fixture)xCGxGxQ=lbinSlidePlate:LxW

5、xPSI(14)xeffectivearea=lbinDesiredResonance:Frequencyx(LxW)/209000=Thickness9/3/20215SpecimenSpecificsSpecimenDescriptionSpecimenTestMassSpecimenDimensionsSpecimenCenterofGravity(CG)SpecimenMountingConsiderationsInadditiontoyourtestspecification,thefollowingtestarticledatai

6、srequiredtodeterminetheappropriatesystemforyourtestrequirements:9/3/20216FixtureSpecificsDoyourfixturesexistorwilltheyrequiredesignandfabrication?Whatareorwillbetheapproximatedimensions(estimateifnecessary)ofthefixturing?Whatisorwillbetheapproximatemass(estimateifnecessary)

7、ofthefixturing?Arethereanymountingissues(boltpattern,size)?Willaheadexpanderberequired?Testfixtureseffectmassandresonanceandmustbeconsideredcarefully.Thefollowingconcernsshouldbeaddressedinselectingashakersystem:9/3/20217ThemaximumAccelerationfortheF=MAestimateisderivedfrom

8、thetestspecification:forSinevibration(G-peak)forRandomvibration(G-rms)forClassical