48640 Machine Dynamics

Requisite(s): 48620 Fundamentals of Mechanical Engineering
Fields of practice: Mechanical Engineering program
Undergraduate
Subject coordinator: Dr Nong Zhang

The objectives of this subject are to give students an understanding of the kinematics and dynamics of rigid bodies in general planar motion, which is typically encountered in design and analysis of mechanical systems, and an elementary understanding of the vibration of mechanical systems, in particular the dynamic behaviour of single-degree-of-freedom mechanical systems with various damping and applied forces. Students should be able to: model problems in rigid body planar and spatial kinematics and rigid body planar dynamics; understand energy methods in contrast to direct applications of Newton's second law of motion for setting up a model; understand the physics of a problem formulated from a real mechanical system; appreciate the role of vibration in machines and structures in the engineering world; understand the procedures required to evaluate a vibration problem; and analyse the dynamic response of single-degree-of-freedom mechanical systems.

The subject also covers: the concept of a rigid body, full nomenclature used in kinematics, two-body velocity equations, velocity pole and velocity diagrams of planar motion; two-body acceleration equations and acceleration diagram; three-body velocity equations and acceleration equations including Coriolis acceleration term; angular velocity acceleration equations including three-dimensional problems; F=ma applied to a rigid-body-dynamics, significance of 'centre of mass', the 'moment' relationship (M=Ia, etc.); angular momentum, conservation of angular momentum (general case, centre of mass moving, no 'fixed' point); linear and angular impulse problems; energy methods for general planar motion; elementary principles of vibration theory, free vibration of undamped single-degree-of-freedom system; free decay vibration of damped single-degree-of-freedom system; and the forced vibration of single-degree-of-freedom system.

Assessment: Typically assessment for this subject involves assignments, quizzes and an examination.

Typical availability

Autumn semester, City campus
Spring semester, City campus
Autumn semester, Hong Kong
Spring semester, Hong Kong
Summer session, Hong Kong
Winter session, Hong Kong