振動力學Office綜合實驗樓1號樓505

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Office:

綜合實驗樓1號樓505研究方向結構動力

（土木、機械、航空航天、車輛）復雜結構隨機振動及其工程應用大跨度結構抗震結構抗風車輛與橋梁動力相互作用噪聲與振動控制振動力2Textbookand

optional

referencesRequired

textbook1.,林家浩.結構動力基礎.大連理工大,

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,

等譯.

結構動力

.

科

,

1985,

2006）Meirovitch

L.

Elements

of

Vibration

ysis

(2nd

Edition).

McGraw-Hill

inc.,

19863振動力Course

requirements

and

gradingCourse

requirements1.

WeeklyPlease

note:

lateassignmentswill

not

be

accepted2.

Final

examinationGrade

components1.

10%2.Final

exam

90%4振動力Vibration?振動力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振動力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振動力hDynamics

and

Vibrationx

1

gt22mx

mgm

tx8振動力hmxhmxkhmxkmx

mg

kxmx

kx

mg2

k

m令x

2

x

gx

g

g

cost2

2mgkx1振動力0hkmxtx

g

g

cost2

2hmxktx

g

g

cost2

22stg

mg

G

xk

ky

x

xstmy

ky

02y

g

costmx

kx

mgy1振動力2所涉及工程領域振動力Vibration

Mechanics,

Mechanics

of

Vibration結構動力Structural

Dynamics,

Dynamics

of

Structures機械工程土木工程航空航天船舶工程車輛工程Mechanical

EngineeringCivil

EngineeringAeronautics

and

AstronauticsShip

EngineeringVehicle

Engineering1振動力3工程中典型的動力荷載環(huán)境荷載、風、浪、流、冰機械運轉車輛行駛沖擊1振動力4EarthquakeWorld’s

Largest

Earthquake

Shake

Test

in

Japan1振動力5WindA

bridge

across

the

Volga

River

in

Volgograd,

Russia1振動力6Ice-induced

vibrationWaveShock水下非接觸1振動力9Running

vehicle汽車行駛平順性飛機座艙CRH5一等座車平面圖2振動力9Vehicle-bridge

dynamic

interactionLaunch

vehicle“但就在火箭上升到三四十公里的高度時，火箭和飛船開始急劇抖動，產(chǎn)生了共振。這讓我感到非常痛苦?！闭駝恿?2單度系統(tǒng)的振動振動力23hmxhmxkmk振動力25單度系統(tǒng)的力

模型kcm彈簧-質量系統(tǒng)kmc2振動力6單擺k/2ck/2m廠房單度系統(tǒng)的力

模型2振動力7單度系統(tǒng)受力分析kmcx(t)F

(t)erF

(t)dF

(t)eF

(t)x(t)m恢復力（Restoring

Force）阻尼力（Dam

Force）Fr

kx(t)Fd

cx(t)粘滯（或粘性）阻尼（Viscous

Dam

）模型R

c

dx(t)

cx(t)dt外力（External

Force）Fe

(t)2振動力8單度系統(tǒng)運動方程根據(jù)第二定律，可以導出F

Fr

Fd

Fe

kx(t)

cx(t)

Fe

(t)

mx(t)將上式整理得mx(t)

cx(t)

kx(t)

Fe

(t)度系統(tǒng)的運動方程（Equation

ofMotion）單rF

(t)dF

(t)eF

(t)x(t)mFr

kx(t)dF

cx(t)2振動力9振動與強迫振動振動（Free

Vibration）體系不受外部的干擾（阻尼除外）作用，僅由初始條件（初位移和初速度）引起的振動。mx(t)

cx(t)

kx(t)

0x(0)

x0

x(0)

x0強迫振動（Forced

Vibration）體系因持續(xù)地受到外部干擾作用發(fā)生的振動。mx(t)

cx(t)

kx(t)

Fe

(t)x(0)

x0

x(0)

x03振動力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無阻尼振動運動方程mx(t)

cx(t)

kx(t)

02

k

m令3振動力10x(t)

x0

sin

t

x

cost12A2

A2

0x202

x2A

x0A1

x0tg

A21A

x0A2

x0振動力32x(t)

Asin(t

)無阻尼振動曲線x(t)

Asin(t

)0x(t)

x0

sin

t

x

cost3振動力3自振頻率或固有頻率（Natural

Frequency）