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탄성체역학
Applied Theory of Elasticity
토목안전환경공학과
옥승용
Week01: Introduction
2
• 옥 승 용 (Ok, Seung-Yong)
• 연구실: 제3공학관 S306호
• 031-670-5282 Fax: 031-670-5289
• E-mail: [email protected]
• Homepage:
– http://cyber.hankyong.ac.kr
– http://www.hknu.ac.kr/web/syok
– http://mail.hknu.ac.kr/guest.jsp
– http://is.hknu.ac.kr → 공학인증(ABEEK) 사이트
• 전반 설문 / 후반 설문
Instructor
3
• Quiz: 20%
• Mid-term Exam: 30%
• Final-term Exam: 40%
• Report: 5%
• Contribution(Attitude, Attendance, etc.): 5%
• Final grades are final. Absolutely no chance to change them by
any excuse except for my mistakes.
• 강의 예절을 지켜주시기 바랍니다.
– Cellular Phone, Text Message, Restroom
– Nodding
Evaluation
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• Class Materials
– will be posted, when necessary, at website
http://mail.hknu.ac.kr/guest.jsp
• Textbooks
– Main Textbook
• 재료역학 (Mechanics of Materials), written by
James M. Gere, Barry J. Goodno, jointly
translated by 김옥환 외 9인, Cengage
Learning
• 정역학과 재료역학(Statics and Mechanics of
Materials), written by F.P. Beer, E.R. Johnston
Jr., J.T. Dewolf, D.F. Mazurek, jointly
translated by 국승규, 최광규, 우광성, 신수봉,
김성보, 1st ed., McGraw-Hill, 도서출판 동화기술
• 재료역학, Gere & Goodno, 교보문고, 공역:
박정선 외
Preparations for Class
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강의노트 준비
3공파일
배포강의노트
개별필기노트
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Class Schedule
Week Topics Remarks
01 Introduction to class Ch. 1
02 Tensile, Compressive and Shear Forces (1) Ch. 1
03 Tensile, Compressive and Shear Forces (2) Ch. 1
04 Tensile, Compressive and Shear Forces (3) Ch. 1
05 Axially Loaded Members (1) Ch. 2
06 Axially Loaded Members (2) Ch. 2
07 Shear Force and Bending Moment (1) Ch. 4
08 Mid-Term Exam
09 Shear Force and Bending Moment (2) Ch. 4
10 Stresses in Beams (1) Ch. 5
11 Stresses in Beams (2) Ch. 5
12 Analysis of Stress and Strain (1) Ch. 7
13 Analysis of Stress and Strain (2) Ch. 7
14 Analysis of Stress and Strain (3) Ch. 7
15 Final-Term Exam
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Curriculum
Mechanics (역학)
Statics (정역학) Dynamics (동역학)
For Rigid body
(강체)
For deformable body
(변형체)
Structural mechanics
(구조역학)
For deformable body
(변형체)
Structural dynamics
(구조진동론)
Earthquake engineering
(내진공학)
Mechanics of materials
(재료역학)or Applied mechanics
(응용역학)
Wind engineering
(내풍공학)
Rigid-body statics2 yr. Rigid-body dynamics
For Rigid body
(강체)
Matrix structural analysis
(매트릭스구조해석)
3 yr.
4 yr.
Graduate
Random vibration
(불규칙진동론)
Finite Element Method
(FEM; 유한요소법)
Theory of Elasticity
(탄성체역학)
Theory of Plate and Shell
(판 및 쉘 이론)
F=KU
MA+CV+KU=F
F=MA
역학
정역학
재료역학
(탄성체역학)
건설안전역학
창의적구조설계
건설구조해석
및 설계
내진공학
및 설계
콘크리트역학 철근콘크리트
구조설계 철골해석
동역학
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Curriculum of Safety Eng. in HKNU
대학수학 일반물리학
및 실험 선형대수학 공업수학
1학년 2학년 3학년 4학년
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• Statics
– Rigid Body
– Truss Structure
• Mechanics of Materials
– Deformable Body
– Beam
• Constructional Safety Mechanics
– Deformable Body
– Truss, Beam and Frame Structures
학습내용
• The science which describes
and predicts the conditions of
rest or motion of bodies under
the action of forces.
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What is Mechanics?
• The science which describes
and predicts the conditions of
rest or motion of bodies under
the action of forces.
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What is Mechanics?
Fundamental Principles
Isaac Newton (1643-1727)
Newton’s Laws of Motion
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13
Newton’s Laws of Motion
• Newton’s First Law: If the resultant force
on a particle is zero, the particle will remain
at rest or continue to move in a straight line.
• Newton’s Second Law: A particle will have
an acceleration proportional to a nonzero
resultant applied force.
F=ma
• Newton’s Third Law: The forces of action
and reaction between two particles have the
same magnitude and line of action with
opposite sense.
Fundamental Principles
Equilibrium
[Statics]
A structure or one of its members
is in equilibrium when it
maintains a balance of force and
moment.
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No motion F=ma=mx0=0
Equilibrium of Structures
Equilibrium (평형조건)이란 힘의 평형상태를 나타내는 것이다.
A Structure is considered to be in Equilibrium, if initially at Rest, and
it remains at Rest when subjected to a System of Forces and Couples.
Equilibrium Conditions = SF=0
Balance of force and moment
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xy
z
xFor equilibrium (6 eqns in general)
0
0
0
z
y
x
F
F
F
0
0
0
z
y
x
M
M
M
Force Moment
Equilibrium of Structures
Equilibrium (평형조건)이란 힘의 평형상태를 나타내는 것이다.
A Structure is considered to be in Equilibrium, if initially at Rest, and
it remains at Rest when subjected to a System of Forces and Couples.
Equilibrium Conditions = SF=0
Equilibrium Equations for a plane structure:
Fx = 0 ; Fy = 0 ; Mz = 0
(on x – y plane)
정정구조해석: 연립방정식 문제
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Free Body Diagram
It is possible to draw many free-body diagrams. Time spent in doing
so is never wasted. (C.H. Norris & J.B. Wilbur & S. Utku)
Free Body Diagram (자유물체도) Create separate diagrams for each of the bodies involved with a clear indication of all
forces (external forces, reaction forces & internal forces) acting on each body.
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Simple Example for FBD
10N
10N
10N
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Simple Example for FBD
10N
10N 10N
10N
10N
10N
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Simple Example for FBD
10N
10N
10N
10N
10N
10N 10N
• Kinetic Units: length, time, mass, and force.
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Systems of Units
구분 SI 단위계 US 상용단위계
Length mm, cm, m, km ft, in
Time s, sec, min, hr
Mass g, kg slug
Force N , kN lb (e.g., 1000lb=1kip)
Stress Pa(=N/m2), Mpa psi, ksi
Moment N∙m lb∙in
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Systems of Units
접두사 도표
접두어 원어 의미
T 테라(terra) 1012 (1조)
G 기가(giga) 109 (십억)
M 메가(mega) 106 (백만)
k 키로(kilo) 103 (천)
h 헥토(hecto) 102(백)
da 데카(deca) 10(십)
1(일)
d 데시(deci) 10-1(십분의 1)
c 센티(centi) 10-2(백분의 1)
m 밀리(milli) 10-3 (1000분의 1)
μ 마이크로(micro) 10-6 (백만분의 1)
n 나노(nano) 10-9 (십억분의 1)
p 피코(pico) 10-12 (1조분의 1)
• 예제
- 1cm = ( ) m
- 1mm3 = ( ) m3
- 1cm2 = ( ) m2
- 2kN = ( ) N
- 25cm × 30MN = ( ) N∙m
- 10kN/500mm2 = ( ) N/m2
= ( ) MPa
*1MPa = 106Pa = 106N/m2
Quiz
• 지름 10mm의 강봉에 20kN의 하중이 작용할 때, 이 강봉의 응력과 변형률을 구하라. 단, 강봉의 탄성계수는 2.0×105MPa이다.
• 지름 15mm의 원형봉에 50kN의 하중이 작용할 때 응력을 구하라.
• 지름 12cm, 길이 24cm의 콘크리트 공시체에 500kN의 압축하중이 작용한다면 이 공시체는 얼마나 줄어들겠는가? 단, 콘크리트의 탄성계수는
21GPa이다.
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Stress:
Strain:
Hooke's Law:
P
A
L P L PLE E L
L A L EA
E
Quiz Announcement
• We will have a short quiz in next class.
– Scope: LN01
– Type: Description & Computation
– Number: 3~5 Problems
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