Course Program
1. Introduction:
• Definition of machines, mechanisms and structures
• Definition of statics and dynamics, kinematics and kinetics
• Definition of links, kinematic pairs and kinematic chains
• Examples of kinematic chains with binary and ternary links
• Lower and higher kinematic pairs: degrees of freedom and construction
• Degrees of freedom of planar and spatial mechanisms: the Grubler and Kutzbach formulas, their applications and limits
2. Analysis of closed chain mechanisms:
• Kinematic analysis via analytical methods
• Kinematic analysis of planar mechanism via graphical methods
• Kinetostatic analysis via analytical methods
• Kinetostatic analysis of planar mechanism via graphical methods
• Applications: the four bar mechanism
• Applications: the single slider crank chain
• Applications: the double slider crank chain (Scotch-Yoke mechanism)
3. Functional analysis of kinematic pairs with friction:
• Prismatic pair: introduction, application and realizations; friction cone; balance of forces; efficiency;
• Inclined plane: balance of forces; efficiency for direct and reverse motion
• Revolute pair: introduction, application and realizations; friction circle; balance of forces; efficiency for direct and reverse motion
• Helical pair with friction: introduction, application and realizations; balance of forces; efficiency for direct and reverse motion
4. Energetics of machines:
• Efficiency of a machines: single machine, machines in series and in parallel, direct and backward motion
• Choice of motor on the bases of useful work
• Mechanical characteristic of machines: definition, measurement, motor-load coupling and its stability
• Start and stop transients of a machine
5. Introduction to MATLAB for the analysis of mechanisms
• Introduction to MATLAB
• Command window, edit window and plot window
• Scripts and functions
• Linear algebra
• Main toolboxes used for the analysis and synthesis of mechanisms (optimization, symbolic…)
• Plot functions
• Examples
6. Functional analysis of mechanical components with wear:
• Reye's hypothesis
• Planar slot (pad brake): introduction, application and realizations; wear profile and pressure distributions
• Planar clutch (automotive clutch): introduction, application and realizations; wear profile and pressure distributions
7. Analysis of machines with flexible elements:
• Cables chains and belts
• Pulley and rope systems (lifting machines): losses, balance of forces and efficiency of systems with fixed and movable pulleys
• Block and tackle systems (lifting machines): balance of forces and efficiency
• Belt transmission: introduction, application and realizations; functioning principles (belt deformation, belt speed, belt-pulley sliding, efficiency); calculation of belt tension; balance of forces; dimensioning
• Cable-driven systems for automation 8. Fundamental equations for the study of the mechanics of machines:
• D’Alembert principle
• Virtual Work principle
• Energy equation
• Lagrange equations
9. Dynamics of machines:
• Kinetic energy, inertia forces and couples of links moving in space and in plane
• Equivalent masses
• Dynamics of the slider crank mechanism: calculation; methods for the compensation of inertia actions (of both first and second order)
• Mechanics of vibrations of spring-mass-dashpot systems: free vibration response of one degree-of-freedom system (calculation and analysis of the response in time domain); forced vibration response of one degree-of-freedom system (calculation and analysis of the response in frequency domain)
10. Analysis of gear mechanisms:
• introduction, application and realizations
• wheels for the transmission of motion between parallel axes: cylindrical gears with straight and helical teeth; generation of gear profiles; pitch and base circles; rack and pinion; nomenclature; transmission ratio; balance of forces; arc of action (calculation); interference condition (calculation); modular and non-modular wheels
• wheels for the transmission of motion between orthogonal and intersecting axes: bevel gears with straight and helical teeth; generation of gear profiles; pitch cones; transmission ratio; Tredgold’s method for the analysis and design of bevel gears
• wheels for the transmission of motion between skew axes: generalities of worm gears (functioning principles and transmission ratio)
11. Applications work groups
• Develop applications of mechanisms by using micro-controllers low-cost sensors with open-source projects.
• Programming with Arduino; Arduino Library, DC Motors, AC Motors, Steppers, Servo Motors, PWM, I2C. s
