Macchine e Meccanismi per l’Industria Sostenibile

The course has the purpose of providing knowledge to the kinematic and dynamic modeling of the main mechanical systems and machines, for the vibrational behavior of systems to one or more degrees of freedom.

Dublin Descriptors

In line with the Study Programme's objective of training students in the field of industrial engineering, this course contributes to the acquisition of the knowledge and skills summarized below.

Knowledge and understanding

Passing the course examination implies that the student has acquired:

• knowledge of the theoretical and practical aspects and the main design methodologies within the field of applied mechanics of machinery;
• the ability to understand problems—including those of high complexity—related to the design and implementation of mechanical and mechatronic systems.

Ability to apply knowledge and understanding:

Passing the course examination implies that the student has acquired the ability to:

• read and interpret drawings and schematics of mechanical systems;
• describe and analyze the static and dynamic behavior of mechanical systems and components;
• identify the most suitable mechanical system solutions for specific applications in industrial and civil contexts;
• evaluate the operating conditions and limitations of key mechanical devices and systems;
• evaluate the operating and usage limits of automation systems used in mechanical installations.

The course will be taught through lectures and classroom exercises, supported by teaching materials (slides, worked exercises, etc.) made available to students at the beginning of and throughout the course.

• Composition mechanisms. General notions of machine and mechanism. Kinematic pairs elementary and superior. Kinematic chains and mechanisms. Degrees of freedom of a mechanism.
• Forces acting in the machines. Work. Efficiency. Energy equation of a machine. Sliding contact between dry surfaces. Application of Coulomb's law. Wear and Reye's hypothesis. Drum brakes and disc brakes. Rolling resistance. Assumption of Hertz. Resistance of vehicles.
• Basic concepts of kinematics and dynamics of a rigid body. Plans motions. Instantaneous rotation center. Statics and dynamics of rigid body in the plane.
• Articulated systems. Determination of velocity and acceleration. Static and dynamic balance. Summary of articulated systems
• Dynamic balance slider-crank.
• Sprockets. Motion transmission with gears. Planetary gear trains and ordinary. Gears. Formula of Willis.
• Flexible members. Stiffness of the flexible members. Hoists. Belts. Belt drives. Brakes tape.
• Mechanical vibrations. Vibrating systems to 1 degree of freedom. Damping. Vibrating systems forced by harmonic forces. Insulation of foundations. Moving harmonic constraint. General methods. Dissipative systems with 2 degrees of freedom free and forced. 

Contribution of the course to the 2030 agenda for sustainable development goals

• SDG 4: Quality Education, Targets 4.3, 4.4, 4.5, 4.6; lectures, in-depth thematic analysis during lessons;
• SDG 9: Industry, Innovation and Infrastructure, Targets 9.1, 9.5; lectures, in-depth thematic analysis during lessons;
• SDG 11: Sustainable Cities and Communities, Target 11.2; lectures, in-depth thematic analysis during lessons.

[1] John J. Uicker, JR. Gordon R. Pennock, Joseph E. Shigley. – Theory of Machines and Mechanisms - Oxford University Press. 

[2] William L. Cleghorn, Nicolai Dechev,- Mechanics of Machines - Oxford University Press.

[3] Course notes of the lessons

Assessment Methods

The written exam consists of three exercises:

1.       Linkage system and statics/dynamics (15points)
3.       Vibrating system (10 points)

The exam is considered passed if a score of at least 18/30 is achieved across the three exercises.

The oral exam consists of answering two questions—one from Group 1 (15 points) and one from Group 2 (15 points)—selected from the list provided in the following section.

The final grade is the arithmetic mean of the written and oral exam scores.

Learning assessment may also be carried out on-line, should the conditions require it.

To ensure equal opportunities and in compliance with current laws, interested students may request a personal interview in order to plan any compensatory and/or dispensatory measures based on educational objectives and specific needs. Students can also contact the CInAP (Centro per l’integrazione Attiva e Partecipata — Servizi per le Disabilità e/o i DSA) referring teacher within their department (https://www.cinap.unict.it/content/referenti).

Group 1 (mechanical systems):

1. Kinematic pairs and mechanisms

2. Contact forces and wear,  Reye's hypothesis 

3. Wear and examples: kinematic skate/plane and supporting revolute pair  

4. Disk brakes

6. Gears 

7.  Gear trains

8.  Belt trasmission, Belts, Chains and joints

9.  Eqs of dynamics (N-E e E-L) 

Gruppo 2 (sistemi vibranti):

10.  1-2 dof  free vibrations

11.  1- 2 dof damped free vibrations, Vibrodyna

12.  1- 2 dof forced vibrations

13.  1-dof vibrating systems Forced vibrations- Applications

14.  2 dof free and forced

15.  Dynamic absorber