重庆大学机械系统动力学ppt1讲解.ppt

* ME Graduate Course: Dynamics * Grade In-class Practice (20%) （A project might be included） Final exam (80%) * Reference Books Advanced Engineering Dynamics (2nd Edition, Jerry Ginsberg, Cambridge University Press 1995) PPT (Pay attention to all the examples) Where to find these materials? dynamics15@126.com Password: dy1111 * Introductory concepts Dynamics: Kinematics and kinetics of particles, rigid bodies and continua Kinematics: Studies motion without its cause Kinetics: Relates forces and torques to motion * Foundations of Dynamics Newton’s laws I. The existence of inertial reference frame II. In an inertial frame, F=ma III. Action and reaction forces are equal and act in opposite directions Apply to particles, systems of particles Rigid bodies/systems of rigid bodies Newtonian mechanics: Motion of bodiesatomic scale Speed of motionsthe speed of light * Two approaches to build equations of motion Vectorial dynamics Newton’s laws Motion is described in physical coordinates and their derivatives Analytical dynamics Lagrangian-Hamiltonian approach (scalar) Newton’s laws to obtain equations of motion * Newton’s laws to obtain equations of motion * Solve by assuming that The equation becomes: Then we will have: Newton’s laws to obtain equations of motion By substituting the initial conditions: * * Lagrange’s equations * * What will be covered? Kinematics Particle kinematics Relative motion Kinematics of rigid bodies Analytical Mechanics Vibration Matlab * Chapter 1. Particle Kinematics Interest is on defining quantities such as position, velocity and acceleration Need to specify a reference frame and a coordinate system in which to actually write the vector expressions. Choose the coordinates naturally fit known aspects of the motion * Cartesian coordinates * * * Cylindrical and polar coordinates * Unit vectors in terms of i, j, k Position Velocity For Acceleration * Spherical Coordinates Position Velocity Acceleration * Extrinsic coordin