


Politecnico di Torino  
Academic Year 2016/17  
02OAKMN Fundamentals of machine construction and drawing 

1st degree and Bachelorlevel of the Bologna process in Mechanical Engineering  Torino 





Subject fundamentals
The aim of the course is to provide the skills and knowledge necessary for the design and verification of mechanical elements, using both traditional and numerical methods and to produce 2D and 3D CAD models and drawings of components and mechanical systems with particular reference to the problems of dimensional and geometric tolerances.
The topics covered are:  Integration of structural mechanics (residual stress, variable amplitude fatigue and basic multiaxial fatigue;  principles and procedures for design and verification of some of the major elements of machines and joints (axes and shafts, axial symmetric solids, hubshaft connections, bearings, springs, threaded fasteners and bolts, welded joints).;  principles and rules of dimensional and geometric tolerancing, criteria for their control and methods for stackup analysis;  methods for functional representation and simulation of industrial projects  matrix structural analysis (linear elastic static problems)  basics of finite element method, with particular reference to the obtained approximations. 
Expected learning outcomes
The aim of the course is to provide the skills and knowledge necessary for the design and verification of mechanical elements, using both traditional and numerical methods and to produce 2D and 3D CAD models and drawings of components and mechanical systems with particular reference to the problems of dimensional and geometric tolerances.
The topics covered are:  Integration of structural mechanics (residual stress, variable amplitude fatigue and basic multiaxial fatigue;  principles and procedures for design and verification of some of the major elements of machines and joints (axes and shafts, axial symmetric solids, hubshaft connections, bearings, springs, threaded fasteners and bolts, welded joints).;  principles and rules of dimensional and geometric tolerancing, criteria for their control and methods for stackup analysis;  methods for functional representation and simulation of industrial projects  matrix structural analysis (linear elastic static problems)  basics of finite element method, with particular reference to the obtained approximations. Knowledge and understanding of mechanical design principles and specific design methodologies for some elements of machines and mechanical joints on the basis of the principal standards. Knowledge of methods of functional representation and simulation of industrial projects; Knowledge of geometric and dimensional tolerancing (GD & T) and of the stackup problems Knowledge of the theory of matrix structural analysis with static loads Knowledge of basic principles of finite element method in linear elastic field for the solution of static problems, with particular reference to the obtained approximations. Ability to perform the design and verification of mechanical elements and connections (axes and shafts, axisymmetric solids, hubshaft connections, bearings, springs, threaded fasteners and bolts, welded joints). Ability to produce manual sketch drawing 2D, computer assisted 3D model and drawing with functional dimensioning by using dimensional and geometric tolerancing in stack ups. Ability to use a FEM code for static linear elastic structural analysis. 
Prerequisites / Assumed knowledge
Knowledge of mechanical engineering drawing according Standards ISO ' ANSI. Ability to interpret drawings of details and assembly. Experience with software CAD 3D
Ability to carry out the kinematic analysis of simple mechanisms, the ability to perform the calculation of stresses in simple mechanical components, to perform static and fatigue verifications, knowledge of the main thermal treatments 
Contents
Topics of this course are herein briefly resumed.
 Fatigue damage. Basic concepts of fatigue, diagrams used in the practice of design, effects affecting the fatigue life of components, notches, safety of structures. Multiaxial fatigue and durability. (9h classes, 6h practice)  Tolerancing and mechanical drawing. Dimensional and geometric tolerances. Chains and standards (6h classes)  Shafts and axes. Stress states, procedures for the prediction of static and fatigue strength of materials. (2h classes)  Gears. Basic principles, geometry of tooth, design of profiles, prediction of actions exchanged between gears with straight and helicoidal teeth patterns, structural analysis, design against fatigue and against wear (6h classes, 3h practice)  Contact mechanics: Results of the theory of Hertz and examples with related application (1.5h classes, 3h practice)  Axissymmetric solids. Stress state in thin walled structures and in thick walled vessels (3h classes, 1.5h practice)  Hubtoshaft fitting. Fitting by interference, under ISO rules within dimensional tolerancing. Tapered keys, keys, pins, parallel key splines. (3h classes, 1.5h practice)  Rolling bearings. Geometry, life and selection from the catalogue of commercial products. Assemblies, rules for assembly and examples. (6h classes, 6h practice)  Connections shaft–to–shaft. Couplings between two shafts and preliminary remarks about their design. Clutches, geometry, design and behavior. (3h classes, 1.5h practice)  Threaded connections. Description, interference diagram, loads due to the clamping, materials. Drawing of threads. Screws and geometries. Load distribution upon the threaded joint (screw and member). Unlocking and uncertainties. Minimum loading condition for members. Shear effect on screws. Static and fatigue strength. (6h classes, 6h practice)  Welded joints. Welding technology. Defects in welded joints. Butt and fillet welds. EuroCode rules to predict the static and the fatigue strength. Variable amplitude loading conditions and Miner’s rule. Standards for threaded joints drawing (4.5h classes, 6h practice)  Springs. Typologies of springs and drawing. Examples with related application. Characteristic curve of spring behavior and effectiveness. Springs in series and in parallel. Torsion bars, helical springs, static and fatigue design. Leaf springs and simplified formulas for design (6h classes, 6h practice) 
Delivery modes
Students will be organized in groups of 3 people during the first week of the class.
Practice hours include some hours spent in solving some numerical exercises and some dedicated to draw the structural elements within CAD  LABs: 1. Practice hours for the part concerning the structural analysis are spent in solving some numerical exercises being dealing with either the design or the verification of machine components. Instructor will solve some exercises as an example of the proposed activity at the blackboard, then students will be required to solve themselves the other proposed exercises, by resorting to the instructor help if needed. Students are strictly required to attend the practice sessions week by week and to solve all the proposed exercises. 2. Practice hours will also used to work to a technical report. Each group will write a unique technical report being related to the assigned work about the design of a mechanical system. Each student will have his own copy of the report and will be required to describe the activity performed, during the oral part of the exam 3. Practice of technical drawing include the study of the function of the designed products and the development of the drawings at the LAIB by resorting to the geometrical modeler Solidworks.. Each group is required to exhibit his collection of drawings, being performed in tight cooperation among all the members of the group. The submitted drawings will be evaluated during the class, before that the class is over. 
Texts, readings, handouts and other learning resources
Textbooks
 Slides of classes  R. Budynas, J. Nisbett, Shigley – Progetto e costruzione di macchine, McGraw Hill, Edizione Italiana (II),2008 e seguenti  M. Rossetto, Introduzione alla fatica dei materiali e dei componenti, Levrotto & Bella, Torino, 2000  E. Chirone, S. Tornincasa, Disegno Tecnico Industriale, vol. II, ed. Il Capitello, 2015  L. Goglio Resistenza dei Materiali e dei Collegamenti, Levrotto & Bella, Torino, 2006 Additional references  R. Giovannozzi, Costruzione di Macchine, voll. 1 e 2, Patron, Bologna, 1980 (storico)  U. Pighini, Elementi Costruttivi delle Macchine, Edizioni Scientifiche Associate, Roma, 1980 (storico)  J.A.Collins, Failure of Materials in Mechanical Design, John Wiley & Sons, 1980 (storico)  R.C. Juvinall, K.M.Marshek, Fondamenti della Progettazione dei Componenti delle Macchine, Edizioni ETS, Pisa, 1993  G. Niemann, H. Winter, Elementi di Macchine, Edizioni di Scienza e Tecnica, Milano, 1986  A. Strozzi, Lezioni di Costruzione di Macchine, Pitagora, Bologna, 1998  S. Suresh, Fatigue of materials, Cambridge University Press, Cambridge, 1998  G. Niemann, H. Winter, B. Höhn, Manuale degli organi delle macchine, Tecniche Nuove, Milano, 2006  R.C. Juvinall, K.M. Marshek, Fundamentals of machine component design, John Wiley & Sons, 2006  A. Riccadonna, M. Todeschini, Disegno, progettazione e tecniche di produzione, Hoepli, 2008.  A. De Paulis, E. Manfredi, Costruzione di Macchine, Ed. Pearson, 2012.  Straneo, Consorti, Disegno, progettazione e organizzazione industriale, Vol. I, II, III ed. Principato  S. Moos, E. Vezzetti, S. Tornincasa, A. Zompì, Quotatura funzionale degli organi di macchine, ed. Clut. 
Assessment and grading criteria
Each student is required to develop the following skills:
1. To be able to perform some preliminary numerical investigations about the design and verification of typical machine elements, by resorting to tables, diagrams and formulas proposed by technical standards and directives; 2. To be able to read and understand basic drawings of mechanical assemblies, exhibiting average complexity, to detect the functions and the behavior of the devices being there depicted; 3. To be able to use the Solidworks tool by introducing all the tolerances required by Standards and useful for manufacturing. The final mark is composed of the evaluation of the two parts ELEMENTS OF MACHINE DESIGN and ELEMENTS OF MACHINE DRAWINGS. Evaluation of the part ELEMENTS OF MACHINE DESIGN The exam consists of two tests :  a written test (score A)  an oral test allowing the student discussing the project developed during the tutorials (score C) Each student must attend both those tests (written and oral) according to the official schedule published online. The oral test is usually straight after the written test. To access to the oral test each student must obtain a score of at least 18/30 in the written test. It is required that both tests are performed in the same exam session (meaning same "appello"). It is compulsory that each student brings at both the written and oral test an identity card and/or the University card with a clear picture in order to be allow verifying his/her identity. During the written test it is compulsory to switch off all the cellphones and any other device able to be connected to the network. Every communication among students in class, or by portable, as well as the use of cheat sheets, of books or notes will be considered a major misconduct. In that case the student will be asked to deliver the examination sheets and to leave the room. At the oral exam each student must provide his/her technical report, complete in all its sections of calculations and drawings. In case of either missing or incomplete technical report the student will be rejected and will perform again both the tests, during another session. Written test The written test consists in:  3 questions each one dealing with a topic of ELEMENTS OF MACHINE DESIGN explained during the classes; the answer must be concise, formulas and graphs are required, books or notes are not allowed;  3 exercises to be solved in numerical form, the exercises are similar to those proposed during the tutorials. The written test is thought to verify the student understanding of topics explained during both lectures and tutorials. It verifies the achievement of a good level in skills 1 and 2. The sheets for the written test are provided to students at the beginning of test. Each student must have all the required tools to write and to draw. At the end of test each student will deliver all the sheets received. The written test is about 2h long, each student can withdraw within 15 minutes since the beginning. Each question and each exercise are evaluated with a score spanning from 0 to 5 points, giving a maximum of 30 points for all of questions and exercises composing the test. This score is herein called Score A. Oral test: The oral test is scheduled usually few days after the written test. 1) Each student can read first his/her written test, being informed by the teaching staff about the grading. During this action the student cannot communicate with other colleagues nor compare answers and results. In case of communication the score could be decreased. However the score of the written test (already decided) could be modified and even slightly increased, in case that the student could demonstrate that during the correction his/her interpretation in some answers or exercise was partially misunderstood. 2) As a second step of the test, each student will be required to defend his/her technical report. Therefore each student must come to the oral test with a copy of the technical report developed in team at home and during the tutorials. That defence will be scored from –2 to +2 points, depending on how the student answers to the questions during the oral test and on the quality and the completeness of the report, which must include all the required drawings. If the student will be unable to show and discuss the technical report during the oral test, the whole exam will be null and will be completely repeated (written and oral tests). This score spanning from –2 to +2 points will be called Score C. Evaluation of the part ELEMENTS OF MACHINE DRAWINGS This evaluation will be based on the judgement of all of drawings performed during the course (one full copy of drawings for each working team of students is required), this evaluation will be done during the classes. The knowledge of theoretical topics explained during the classes will be evaluated during three tests assigned to the students in three different days during the semester. Evaluation of both the tests and of drawings will lead to a final score up to a maximum of 30/30. This score will be herein called Score B. If the student does not pass the tests, this evaluation will require an additional oral test, being performed at the dates officially scheduled. It deals with all the topics proposed during the classes and the tutorials of ELEMENT OF MACHINE DRAWINGS. Final score of the integrated exam The score of the part ELEMENTS OF MACHINE DESIGN will be averaged with the score of the part ELEMENTS OF MACHINE DRAWINGS according to credits assigned to each part as follows : Final score = 2/3*(Score A+Score C) + 1/3*Score B If the final score will be higher than 30/30, "laude" (lode) could be assigned upon judgment of the evaluation committee eventually by asking the student one or two questions, about all the topics explained during the classes. 
