33928 - Machine Mechanics M

Learning outcomes

Students will be able to understand the principles of monitoring and diagnostics of mechanical systems.

Course contents

Elements of rigid body dynamics. Momentum and moment of momentum. Inertia force and inertia couple. Kinetic energy. Kinetics of the four-bar linkage. Inverse dynamic problem. Basic equations of Dynamics. Kinetic analysis of a R-R robot manipulator.

Vibrations of systems with one degree of freedom. Free vibrations. Energy methods and Rayleigh method. Forced oscillations with viscous damping. Energy dissipated by damping. Logarithmic decrement and half-power side. Vibration isolation. Base excitation. Impulse excitation.

Two degrees of freedom systems. Free vibrations. Normal mode vibration. Coordinate coupling. Forced har

Several degrees of freedom. Mass matrix and stiffness matrix. System or dynamic matrix. Eigenvalues and eigenvectors. Orthogonal properties of the eigenvectors. Modal matrix and principal coordinates. Proportional damping. Forced vibrations and modal approach.

Vibrations of continuous systems. Vibrating string. Longitudinal vibration of rods. Transverse free vibration of bars. Forced vibration of a beam. Free vibration of membranes. Local modal sensitivity of rods and beams.

Modeling and simulation of mechanical systems. Modeling of rods, shafts and beams. Modeling and simulation of mechanisms. Use of Simulink Ó.

Introduction to finite element method. Discretization. Bar element. Assembly of elements. Displacement function. Boundary conditions. Beam element. Examples of dynamic analysis by finite element method.

Vibration measurement. Vibration measuring instruments. Signal analysis. Fourier analysis. Acquisition parameters. Synchronous averaging. Windowing. Frequency response function. Introduction to experimental modal analysis. Health effects of vibration.

Rotor dynamics. Balancing of rigid rotors.Bending critical speeds of simple shafts. Out-of-balance response of rotors. Gyroscopic effects. Shafts with dissimilar moments of area.

Diagnostics of machines.An introduction to maintenance for mechanical systems.Principles of random data analysis and measurement. Vibration transducers. Diagnostics: rolling bearings and fluid film bearings; gears: unbalance; rotors.

Readings/Bibliography

-U. Meneghetti, A. Maggiore, E. Funaioli, "Lezioni di Meccanica applicata alle macchine. Terza parte: Dinamica e vibrazioni delle macchhine", Patron Editore, Bologna, 2010, ISBN978-88-555-3092-7
-Lecture notes.

Teaching methods

The course is based on both academica and practical lessons.

Assessment methods

The final test consists in an oral interrogation.

Teaching tools

Overhead projector, PC, videoprojector.

Office hours

See the website of Alberto Maggiore

See the website of Umberto Meneghetti