應用力學 ( 二 ) Dynamics 朱銘祥教授

Instructor: Prof. Ming-Shaung Ju ( 朱銘祥教授 ) (ME Building 7th F Room 727, ext 62163) Instructor: Prof. Ming-Shaung Ju ( 朱銘祥教授 ) (ME Building 7th F Room 727, ext 62163) Office hours: Thursday 2PM, Friday 2PM Office hours: Thursday 2PM, Friday 2PM Teaching Assistant: 黃繪禎 助教 (ME Building 12th F Room C11, ext 62263) Teaching Assistant: 黃繪禎 助教 (ME Building 12th F Room C11, ext 62263) Textbook: R. C. Hibbeler, Engineering Mechanics: Dynamics, 12th Ed., Textbook: R. C. Hibbeler, Engineering Mechanics: Dynamics, 12th Ed., Reference: J.L. Meriam, Engineering Mechanics: Dynamics, 6th Ed., Reference: J.L. Meriam, Engineering Mechanics: Dynamics, 6th Ed., 2008.

What is Dynamics? Branch of mechanics which deals with the motion of bodies under the action of forces

Mechanics Statics – effects of forces on bodies at rest Statics – effects of forces on bodies at rest Dynamics Dynamics Kinematics – study of motion of bodies without reference to forces which cause the motion Kinematics – study of motion of bodies without reference to forces which cause the motion Kinetics – relates action of forces on bodies to their resulting motion Kinetics – relates action of forces on bodies to their resulting motion

History of Dynamics Galileo Galilei, Issac Newton, Leonhard Euler, Joseph L. Lagrange,

Applications of Dynamics Modern machines and structures operated with high speed (acceleration) Modern machines and structures operated with high speed (acceleration) Analysis & design of Analysis & design of Moving structure Moving structure Fixed structure subject to shock load Fixed structure subject to shock load Robotic devices Robotic devices Automatic control system Automatic control system Rocket, missiles, spacecraft Rocket, missiles, spacecraft Ground & air transportation vehicles Ground & air transportation vehicles Machinery Machinery Human movement Human movement

Procedures 1. Read the problem & correlate actual physical situation with theory 2. Draw any necessary diagram (e.g. free-body) & tabulate problem data 3. Establish a coordinate system (reference frame) & apply relevant principles (mathematical form) 4. Solve necessary equations algebraically then use a consistent set of units & complete the solution 5. Study the answer using technical judgment & common sense 6. Review the problem.

Example: pendulum

Outline 2/20 Introduction & Kinematics of a particle 3/7 Kinetics of a particle: Force and Acceleration 3/14 Kinetics of a particle: Work and Energy 3/26 Kinetics of a particle: Impulse and Momentum 4/9 Planar kinematics of a Rigid Body 4/23 Planar kinetics of a Rigid Body: Force and Acceleration

Outline (cont ’ d) 5/7 Planar kinetics of a Rigid Body: Work and Energy 5/16 Planar kinetics of a Rigid Body: Impulse and Momentum 5/28 Three-Dimensional Kinematics of a Rigid Body & Overview of 3D Kinetics of a Rigid Body 6/13 Vibrations: under-damped free vibration, energy method, undamped forced vibration, viscous damped vibrations

Grading Quiz and Homework 20% Quiz and Homework 20% 1st Midterm 25% 1st Midterm 25% 2nd Midterm 25% 2nd Midterm 25% Final Exam 35% Final Exam 35% Total = 105% ?? Total = 105% ??

Notes: Suggest to take lecture notes! Suggest to take lecture notes! Homework be assigned on a weekly basis, a quiz after a Chapter is finished Homework be assigned on a weekly basis, a quiz after a Chapter is finished Homework should be hand-written Homework should be hand-written Solutions to homework problem set will also be post at FTP ( ； Port ： 21 ； user: student, password: student) Solutions to homework problem set will also be post at FTP ( ； Port ： 21 ； user: student, password: student)