|Politecnico di Torino|
|Academic Year 2015/16|
Fundamentals of machine design and drawing
1st degree and Bachelor-level of the Bologna process in Automotive Engineering - Torino
The course aims at providing further notions/ concepts/knowledge to what was learned in the base course of mechanical drawing. The course provides the basics on CAD systems, on the methods for using such systems, on the possibility of integration and on the lines of evolution of IT systems to support the design and documentation phase.
The course also aims at providing the fundamentals of machine component design and analysis, with particular reference to machine components used in vehicles and to their integration into complex systems. Strength of materials under static, dynamic, thermal and fatigue loads is also part of the course objectives.
Expected learning outcomes
Students are expected to develop the operative ability of using a system of the latest generation for three-dimensional modeling .
Students are also expected to acquire the knowledge related to the methodologies for the design of some of the major elements of machines and of mechanical systems, taking into account the different types of applied loads (mission) and their interaction with other parts of the same machine (system).
Prerequisites / Assumed knowledge
Fundamentals of informatics or Computer Science
Fundamentals of strength of materials,
Science and technology of materials or Technology of metallic materials
Complements of technical industrial drawing: application of functional and technological dimension specification system to product parts.
Computer Aided Design and Manufacturing (CAD-CAM)
- General information on CAD systems.
- Hardware: overview of systems, peripherals, graphical input systems.
- Software: interactive graphical packages, two-dimensional and three-dimensional systems.
- Physical parts, models and representations.
- The CAD-CAM process. The problems of integrating CAD-CAM-CAE.
Elements of Computer Graphics
- Notes on basic algorithms for geometric transformations: translation, rotation and scale.
The geometric modeling
- 2D and 3D models, wireframe, B-Rep and CSG.
- Parametric curves and surfaces: Bezier curves and surfaces, spline, B-spline, NURBS;
- Modeling system from geometry based to knowledge based: feature-based systems.
Methods and technologies for the integration
- The process of project development. PDM systems, Digital Mock-up. The problem of data exchange: the transfer of data between different CAD systems, the IGES and STEP standards.Strength of materials
- Recall of the calculation of equivalent stress and possible failure modes
- Basics of fatigue strength of materials; factors influencing the fatigue life, fatigue characteristic data and standard diagrams; stress concentration due to notches; load time histories, damage and damage accumulation.
- Hertz theory for the calculation of the contact pressure, strength of materials to contact loads and wear problems
- Threaded joints, axial load and tightening torque, static and fatigue design
Machine elements and their design
- Roller bearings: choice in the catalog, life estimation, assembly and site preparation
- Torsion bars, cylindrical helical springs, leaf springs, conical disc springs
- Notes on friction clutches and transmission joints: articulated, universal and homokinetic joints
- Cylindrical spur gears, tooth involute profile, modular geometry, length of the path of contact, contact ratio, transmission ratio, specific sliding coefficients, gear tooth bending and surface fatigue failure.
Students will develop in the classroom exercises on the topics covered during lectures.
Solid modeling of mechanical components using feature-based CAD systems. Assembly of components. Documentation of components and assemblies using two-dimensional drawing.
Students will also be asked to develop small projects related to motor vehicle parts, so to apply in a comprehensive/integrated way some of the methods for design and verification.
Students will develop applications of CAD drawing taking advantage of the PLM and TC packages specifically installed in the computer Labs of Mirafiori site.
Texts, readings, handouts and other learning resources
Slides and notes will be made available to students
- Foley, van Dam, Feiner, Hughes - Computer Graphics: Principles and Practice, Addison-Wesley - 1997
- Jami J. Shah, Martti Mäntylä - Parametric and Feature-Based CAD / CAM - John Wiley & Sons - 1995
- Michael E. Mortenson - Geometric Modeling - Second Edition - John Wiley & Sons, 1997
- E. Chirone, S. Tornincasa - Disegno tecnico industriale, vol. I e II - Il capitello, Torino, 2010
- A.R. Juvinall, K.M. Marshek - "Fundamentals of machine component design", Wiley
- M. Rossetto - "Introduzione alla fatica", ed. Levrotto & Bella, Torino
- J. Bannantine – "Fundamentals of metal fatigue analysis", Prentice Hall 1990
Further reference books
- R. Giovannozzi - "Costruzione di Macchine", ed. Patron, Bologna
- J.A. Collins - "Failure of materials in mechanical design", ed.
Wiley, New York
- Wahl - "Mechanical springs"
Assessment and grading criteria
The final exam is devoted to evaluate the knowledge acquired both in Machine design and in Drawings
For what concerns Drawing the exam consists in a practical test in the CAD laboratory, that includes the evaluation of exercises carried out during the course, and in a written test. To pass this part of the exam, students must obtain "pass" both in the practical test and in the written test..
For what concerns Machine design, the exam consists in a written part and an oral part.
The written part generally consists in the solution of a couple of design and verification problems. During the tutorials, students will develop the solution of problems similar to those they will be asked to solve during the written exam. The oral part of the exam is devoted to verify the level of knowledge of the Machine Design topics that have been taught during the lectures. The ability of the student to explain from the theoretical point of view the asked questions, making use of formulas and diagrams, is of particular importance. It is also of relevance the ability of the student to explain technical constructive solutions by means of pencil sketches.
To pass the written test students have to obtain a evaluation equal or larger than 18/30 for each of the problems that the written test is made of. In order to take the oral exam, the candidate must have passed the written test. The written and oral parts of Machine Design have to be passed in the same exam session.
Programma definitivo per l'A.A.2015/16