講質點系統(tǒng)結構分析

Chapter13質點系統(tǒng)結構分析AnalysisofLumpedMassSystems2/31Contents13.1 與質點結構系統(tǒng)有關的元素

ElementsforMass-Spring-DamperSystems13.2 實例:登陸系統(tǒng)的彈簧及組尼設計

DesignofSpring/DamperinaRecoilLandingSystem13.3 實例:磅秤的組尼設計

Example:DesignofDamperinaSpringScale13.4 實例:淬火溫度分析

Example:QuenchingofaShaft13.5 與質點系統(tǒng)相關的元素

ElementsRelatedtoLumped-MassSystems3/31第13.1節(jié)與質點結構系統(tǒng)有關的元素ElementsforMass-Spring-DamperSystems4/3113.1.1MASS21:StructuralMassElementNameMASS21NodesIDegreesofFreedomUX,UY,UZ,ROTX,ROTY,ROTZifKEYOPT(3)=0

UX,UY,UZifKEYOPT(3)=2

UX,UY,ROTZifKEYOPT(3)=3

UX,UYifKEYOPT(3)=4RealConstantsMASSX,MASSY,MASSZ,IXX,IYY,IZZifKEYOPT(3)=0

MASSifKEYOPT(3)=2

MASS,IZZifKEYOPT(3)=3

MASSifKEYOPT(3)=4MaterialPropertiesNoneSurfaceLoadsNoneBodyLoadsNoneSpecialFeaturesLargedeflectionKEYOPT(2)KeyforelementcoordinatesystemKEYOPT(3)0-3-Dmasswithrotaryinertia

2-3-Dmasswithoutrotaryinertia

3-2-Dmasswithrotaryinertia

4-2-Dmasswithoutrotaryinertia5/3113.1.2COMBIN14:Spring/DamperElementNameCOMBIN14NodesI,JDegreesofFreedomUX,UY,UZifKEYOPT(3)=0

ROTX,ROTY,ROTZifKEYOPT(3)=1

UX,UYifKEYOPT(3)=2

etc.RealConstantsK,CV1,CV2MaterialPropertiesNoneSurfaceLoadsNoneBodyLoadsNoneSpecialFeaturesNonlinear(ifCV2isnotzero),Stressstiffening,Largedeflection,etc.KEYOPT(1)0-LinearSolution(default)

1-Nonlinearsolution(requiredifCV2isnon-zero)KEYOPT(3)0-3-Dlongitudinalspring-damper

1-3-Dtorsionalspring-damper

2-2-Dlongitudinalspring-damper(2-DelementsmustlieinanX-Yplane)6/3113.1.3EquivalentMass/Spring/DamperTranslationalSystemsRotationalSystemsKineticEnergyPotentialEnergyDissipatedEnergy7/31第13.2節(jié)實例:登陸系統(tǒng)的彈簧及阻尼設計DesignofSpring/DamperinaRecoilLandingSystem8/3113.2.1ProblemDescriptionVehiclemassMPistonCylinderDamperDSpringKRodFoot9/3113.2.2ModelingConsiderationsyDKM10/3113.2.3EquivalentSpring/DamperyDLKq11/3113.2.4ANSYSProcedure(1/2)0102030405060708091011121314151617181920FINISH/CLEAR/TITLE,RecoilLandingSystem(SI)/PREP7

K

=72000

M

=2000

D

=24000

!Criticallydamped

V0=5

!18km/Hr

ET,1,COMBIN14,,,2

ET,2,MASS21,,,4

R,1,K,D

R,2,M

N,1,0

!Ground

N,2,1

!Vehicle

TYPE,1$REAL,1$E,1,2

TYPE,2$REAL,2$E,2

FINISH12/3113.2.4ANSYSProcedure(2/2)22232425262728293031323334353637383940

/SOLU

ANTYPE,TRANS

TRNOPT,FULL

D,ALL,UY,0

D,1,UX,0

IC,2,UX,0,-V0

DELTIM,0.01

TIME,2

OUTRES,NSOL,ALL

SOLVE

FINISH/POST26

NSOL,2,2,U,X,DISP

/GRID,1

/AXLAB,Y,DISPLACEMENT

PLVAR,213/31第13.3節(jié)實例:磅秤的阻尼設計DesignofDamperinaSpringScale14/3113.3.1ProblemDescriptionItemplacedonplatformmassmPlateformmassMpSpringKmassMkRackmassMrDamperDmassMdCalibrateddialJcGearrationGearedmagnifierJgR15/3113.3.2ModelingConsiderationsItemmScaleMSpringKDamperDy16/3113.3.3LumpedMasses(1/4)

LumpedMassforaSpringLVoVxdmEquivalentlumpedmassMeq17/3113.3.3LumpedMasses(2/4)

LumpedMassforaGear-and-RackSetRMrJGVoRollswithoutslipping18/3113.3.3LumpedMasses(3/4)

LumpedMassforaGearedShaftsSetJ1J2N1N2JeqGearsShafts19/3113.3.3LumpedMasses(4/4)

LumpedMassfortheSpringScaleSystemGearset20/3113.3.4ANSYSProcedure(1/2)0102030405060708091011121314151617181920FINISH/CLEAR/TITLE,SpringScale(cgs)/PREP7

m

=1500

!G

Meq=500

!G

K

=3.2E6

!dyn/cm

D

=6.4E4

!dyn-s/cm

ET,1,COMBIN14,,,2

ET,2,MASS21,,,4

R,1,K,D

R,2,m+Meq

N,1,0

N,2,1

TYPE,1$REAL,1$E,1,2

TYPE,2$REAL,2$E,2

FINISH21/3113.3.4ANSYSProcedure(2/2)22232425262728293031323334353637383940

/SOLU

ANTYPE,TRANS

TRNOPT,FULL

DELTIM,0.02

TIME,2

KBC,1

D,ALL,UY,0

D,1,UX,0

F,2,FX,-m*981

OUTRES,NSOL,ALL

SOLVE

FINISH/POST26

NSOL,2,2,U,X,DISP

/GRID,1

PLVAR,2

22/31第13.4節(jié)實例:淬火溫度分析QuenchingofaShaft23/3113.4.1ProblemDescriptionT(0)Tb(0)

T(t)Tb(t)ShaftBathmb=1lbBeforequenchingAfterquenchingms=0.069lb24/3113.4.2ModelingConsiderationsms,Cs,Tsmb,Cb,Tbh,A25/3113.4.3ANSYSProcedure(1/2)0102030405060708091011121314FINISH/CLEAR/TITLE,Unit:lb(mass)-ft-(Btu)-hr-F/PREP7

PI=4*ATAN(1)

ET,1,MASS71

R,1,PI*(1/4/12)**2/4*(5/12)

MP,DENS,1,486

MP,C,1,0.11

ET,2,LINK34

R,2,0.028

MP,HF,2,300161718192021222324252627282930

ET,3,MASS71,,,1

R,3,1/62

MP,DENS,3,62

MP,C,3,1.0

N,1,0

N,2,1

TYPE,1$REAL,1$MAT,1

E,1

TYPE,2$REAL,2$MAT,2

E,1,2

TYPE,3$REAL,3$MAT,3

E,2

FINISH26/3113.4.3ANSYSProcedure(2/2)3233343536373839404142434445464748495051

/SOLU

ANTYPE,TRANS

TRNOPT,FULL

DELTIM,0.0001

KBC,1

TIME,0.01

IC,1,TEMP,1300

IC,2,TEMP,75

OUTRES,NSOL,ALL

S