Ship Vibration and Rotor-dynamics

At the end of this course, the students should be able to: 1. explain the phenomena of ship and shaft vibrations, modes, causes, effects, and attenuation procedures; 2. distinguish between torsional and lateral vibrations, free and forced vibration of single- degree and multi-degree of freedom systems; 3. calculate vibration parameters such as inertia, damping and stiffness coefficients; natural frequency, magnification, log decrement, etc; 4. apply both numerical and analytical methods for analysing multi-degree of freedom shafts; and 5. utilise vibration measuring instruments for measuring vibration modes, amplitude, frequency, phase angle and critical speed.

The phenomenon of vibration. Various modes of vibration onboard (free, forced, transverse, axial torsional – Their sources and effects), Free and forced vibration of single degree of freedom systems, natural frequency, damping, damping ratio and log decrement, base excitation, free and forced vibration of multi-degree of freedom systems, and vibration absorber. Numerical methods for multi-degree of freedom systems of shafts. Ship vibration and effects. Introduction to transient vibration theory, analysis and computer simulation. Vibration measuring instruments. Noise and vibrations: Elements of aerodynamic and hydrodynamic sources, noise and vibration suppression techniques, noise level measurement. Resonance and critical speed. Anti-vibration mountings of machines. Dampers with reference to torsional and lateral vibrations.