振动力学Office综合实验楼1号楼505

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Office:

综合实验楼1号楼505研究方向结构动力

（土木、机械、航空航天、车辆）复杂结构随机振动及其工程应用大跨度结构抗震结构抗风车辆与桥梁动力相互作用噪声与振动控制振动力2Textbookand

optional

referencesRequired

textbook1.,林家浩.结构动力基础.大连理工大,

2007Reference

textbooksThomson

W

T,

Dillon

D

M.

Theory

of

Vibration

with

Applications.

NewJersey:

Prentice

Hall,

1998Clough

RW,

Penzien

J.

Dynamics

of

Structures

(Third

Edition).Computers

&

Structures

Inc.,

2003（

RW等著,

等译.

结构动力

.

科

,

1985,

2006）Meirovitch

L.

Elements

of

Vibration

ysis

(2nd

Edition).

McGraw-Hill

inc.,

19863振动力Course

requirements

and

gradingCourse

requirements1.

WeeklyPlease

note:

lateassignmentswill

not

be

accepted2.

Final

examinationGrade

components1.

10%2.Final

exam

90%4振动力Vibration?振动力5MechanicsOxford

Advanced

Learner’s

Dictionarythe

science

ofmovement

and

forcethe

practical

study

of

machinerythe

way

something

works

or

is

doneWikipedia

(

)Mechanics

is

the

branch

of

physics

concerned

with

the

behavior

of

physical

bodies

when

subjected

to

forces

or

displacements,

and

the

subsequent

effects

of

the

bodies

on

their

environment.

The

discipline

has

its

roots

in

several

ancientcivilizations.

During

the

early

modern

period,

scientists

such

as

Galileo,

Kepler,and

especially

Newton,

laid

the

foundation

for

what

is

now

known

as

classicalmechanics.6振动力VibrationKinematicsKinematics

is

that

branch

of

physics

which

involves

thedescription

of

motion,

without

examining

the

forces

whichproduce

the

motion.Kinetics

(Dynamics)Dynamics

(the

nearly

synonymous

name

is

kinetics),

on

theother

hand,

involves

an

examination

of

both

a

description

ofmotion

and

the

forces

which

produce

it.VibrationVibration

refersequilibrium

point.to

mechanical

oscillations

about

an7振动力hDynamics

and

Vibrationx

1

gt22mx

mgm

tx8振动力hmxhmxkhmxkmx

mg

kxmx

kx

mg2

k

m令x

2

x

gx

g

g

cost2

2mgkx1振动力0hkmxtx

g

g

cost2

2hmxktx

g

g

cost2

22stg

mg

G

xk

ky

x

xstmy

ky

02y

g

costmx

kx

mgy1振动力2所涉及工程领域振动力Vibration

Mechanics,

Mechanics

of

Vibration结构动力Structural

Dynamics,

Dynamics

of

Structures机械工程土木工程航空航天船舶工程车辆工程Mechanical

EngineeringCivil

EngineeringAeronautics

and

AstronauticsShip

EngineeringVehicle

Engineering1振动力3工程中典型的动力荷载环境荷载、风、浪、流、冰机械运转车辆行驶冲击1振动力4EarthquakeWorld’s

Largest

Earthquake

Shake

Test

in

Japan1振动力5WindA

bridge

across

the

Volga

River

in

Volgograd,

Russia1振动力6Ice-induced

vibrationWaveShock水下非接触1振动力9Running

vehicle汽车行驶平顺性飞机座舱CRH5一等座车平面图2振动力9Vehicle-bridge

dynamic

interactionLaunch

vehicle“但就在火箭上升到三四十公里的高度时，火箭和飞船开始急剧抖动，产生了共振。这让我感到非常痛苦。”振动力22单度系统的振动振动力23hmxhmxkmk振动力25单度系统的力

模型kcm弹簧-质量系统kmc2振动力6单摆k/2ck/2m厂房单度系统的力

模型2振动力7单度系统受力分析kmcx(t)F

(t)erF

(t)dF

(t)eF

(t)x(t)m恢复力（Restoring

Force）阻尼力（Dam

Force）Fr

kx(t)Fd

cx(t)粘滞（或粘性）阻尼（Viscous

Dam

）模型R

c

dx(t)

cx(t)dt外力（External

Force）Fe

(t)2振动力8单度系统运动方程根据第二定律，可以导出F

Fr

Fd

Fe

kx(t)

cx(t)

Fe

(t)

mx(t)将上式整理得mx(t)

cx(t)

kx(t)

Fe

(t)度系统的运动方程（Equation

ofMotion）单rF

(t)dF

(t)eF

(t)x(t)mFr

kx(t)dF

cx(t)2振动力9振动与强迫振动振动（Free

Vibration）体系不受外部的干扰（阻尼除外）作用，仅由初始条件（初位移和初速度）引起的振动。mx(t)

cx(t)

kx(t)

0x(0)

x0

x(0)

x0强迫振动（Forced

Vibration）体系因持续地受到外部干扰作用发生的振动。mx(t)

cx(t)

kx(t)

Fe

(t)x(0)

x0

x(0)

x03振动力0mx(t)

kx(t)

0x(t)

2

x(t)

0x(t)

A

sin

t

A

cost

Asin(t

)1

2x(t)

A

cost

A

sin

t

A

cos(t

)1

2x(0)

x0

x(0)

x0无阻尼振动运动方程mx(t)

cx(t)

kx(t)

02

k

m令3振动力10x(t)

x0

sin

t

x

cost12A2

A2

0x202

x2A

x0A1

x0tg

A21A

x0A2

x0振动力32x(t)

Asin(t

)无阻尼振动曲线x(t)

Asin(t

)0x(t)

x0

sin

t

x

cost3振动力3自振频率或固有频率（Natural

Frequency）