The aim of the subject is to provide the skills and knowledge necessary for the design and verification of mechanical elements, using both traditional and numerical methods . The topics covered are: - integration of structural mechanics (residual stress, variable amplitude fatigue and basic multi-axial fatigue; - principles and procedures for design and verification of some of the major elements of machines and joints (axes and shafts, axial symmetric solids, hub-shaft connections, bearings, springs, threaded fasteners and bolts, welded joints);

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; Ability to perform the design and verification of mechanical elements and connections (axes and shafts, axisymmetric solids, hub-shaft connections, bearings, springs, threaded fasteners and bolts, welded joints);

Ability to understand mechanical drawings. Ability to carry out the kinematic analysis of simple mechanisms, ability to perform the calculation of stresses in simple mechanical components and to perform static and fatigue verifications, knowledge of the main thermal treatments.

The aim of the subject is to provide the minimum skills and knowledge necessary for the design and verification of mechanical elements and it represents the straight development and insight of the contents of the subject Fundamental of Strenght of Materials towards applications of machine design. The calculations for the design of machine elements are developed for all the machine elements typical of the machine design subjects. This subject is organized to provide the skills to define the strength of machine elements is taken into account by means of calculations and design procedure against static and dynamic (fatigue) stress. The commonest machine elements and joint elements are considered. Lectures will give a straight presentation of relevant topics to be studied to perform design of machines through verification of the components and of the system. Practice hours will be offered to solve examples, numerical exercises and practical cases, practice with machine design and tools, and an exam simulation. • Course Organization o Introduction to the subject: contents, basic knowledge requirements, classes, practice (exercise), exam (1 h). o Fatigue: stress concentration, basic concepts, engineering fatigue diagrams, fatigue life and fatigue strength influencing factors, multiaxial loading, components safety (9 hours). o Spindles and shafts: stress states, computation and verification methods (3 hours). o Gearing: basics, tooth geometry, force calculation, determination of meshing forces and stress loading for spur and helical gears (2.5 hours). o Stress state for contact loads: basics of Hertz theory and applications (design procedures and fatigue verification according to AGMA standards) (2.5 hours). o Axisymmetric solids: stress state in thin walled tubes subjected to pressure load, stress field in axisymmetric solids, tubes and thick walled pressure vessels. (3.5 hours). o Hub-shaft fitting: interference assembly, use of ISO tolerancing tables for stress state calculation, connecting elements, Shaft-hub connections by keys, splines, pins, etc. (4.5 hours). o Bearings: types, catalogue selection, endurance evaluation, mounting solutions (3.5 hours). o Shaft joints and clutches: main connection methods, permanent and moveable (6.5 hours). o Threaded connections: description and standards, interference diagrams, stresses in the threaded connectors, effect of external loading, uncertainty and loosening, anti-loosing methods, static and fatigue verifications (4.5 hours). o Welding: processes and methods, types of welding, static and fatigue verifications with Eurocodes, variable loading, Miner rule. (4.5 hours). o Springs: types of springs, applications, utilization factor, springs in series and in parallel, torsion springs, leaf springs, static and fatigue verification (4.5 hours). o Tutoring, subject completion, example of a test exam (4.5 hours).

At the end of the semester , the student gains the knowledge of the commonest machine components used in the mechanical field and a variety of constructive solutions for each topics included in the subject. Preliminary dimensioning and verifications and the skill of representing in a clear way what he calculated are also objectives of the subject. It is expected that the student achieves specific skills such as: 1. To perform preliminary verification and dimensioning calculations on the main machine components, with the aid of tables, diagrams and formulas from technical codes and standards; 2. To read and understand drawings of assembly of medium complexity and understand how the represented devices work; The knowledge of the basic concepts, of the experimental techniques and of the technological framework at the origin of the theory, standards, and simplifying assumptions, constitutes a main part of the professional background even if it is not described in a mathematical form. These aspects are therefore part of the exercise lectures which are divided into two parts: • Assisted exercises on the topics of machine design: The ability to solve real problems that an engineer must face in his professional life is achieved by developing the ability to apply theoretical models to practical applications. Thus, exercises for the part of machine design propose simple but realistic problems whose objective is to lead the student to a full comprehension of the theoretical basis to use it in everyday professional life. Exercises allow to get the sensitivity of the order of magnitudes of the values that are calculated on the final result. In this sense it is vividly suggested, during the lectures where exercises are presented and during the written part of the final exam, to also use graphical solutions also and to perform the analysis of the dimension units in order to avoid wrong conclusions determined by computation errors. Exercises will be shown and solved partly by the teacher and partly by students during the classes dedicated to this part. • Homework project: the development of a mechanical system project aims at approaching the professional life of a mechanical engineer. One or more parts of a mechanical system (usually a transmission line for speed reduction) will be designed. All the various parts (gears, shafts, supports, connections, etc.) will be subject to verification for strength, in static loading and fatigue, to insure an adequate level of safety against failure. The system will be drafted together with the details of the parts that compose the system. This homework project will be developed in team-working, by teams of 3 students. Each student shall contribute equally to the development of the project, and will be equally responsible for the quality and validity results. The main fulfillment of this homework project will be the preparation of a written homework technical report of the design flow and of all the calculations and verifications made. The homework technical report, possibly printed or written in high quality standard, will include the tables, calculations and technical description. The report shall be delivered before the end of the semester (end of the lectures): failure to comply with this deadline will prevent participation to the exams. Delivery will be fulfilled in electronic form according to specifications that will be detailed during the course. The report will be evaluated and rated for what concern the design and drawing contents: rating is indicated in the following, in the section dedicated to the exams rules. A minimum acceptable quality for the report is strictly requested. The teachers will evaluate the outcome of the homework project that is reported in the technical report, and can reject it: in this case the exam will not be recorded, even in the case of a positive result, and must be repeated until an acceptable report is presented within the same date of the written exam and rated.

Material used by the lecturers during the lectures, and distributed through the university portal. Notes directly taken from the classes will be shared with students through the website. Electronic resources that can be found in the internet will be also suggested. Main study references: • Budynas, R., Nisbett, J., Shigley’s Mechanical Engineering Design, 8th Edition in SI units, McGraw Hill, 2008 • Juvinall, R.C., Marshek, K.M., Fundamentals of machine component design, 4th Edition, Wiley, 2006 • Childs, P.R.N., Mechanical Design, 2nd Edition, Elsevier, 2004 (also in eBook format, see library website) • Rossetto, M., Introduzione alla fatica dei materiali e dei componenti, Levrotto & Bella, Torino, 2000 • Goglio, L., Resistenza dei Materiali e dei Collegamenti, Levrotto & Bella, Torino, 2006 • Collins, J.A., Failure of Materials in Mechanical Design, 2nd Edition, Wiley, 1993 Additional textbooks: • Suresh, S., Fatigue of materials, Cambridge University Press, 1998 • Niemann, G., Winter, H., Maschinenelemente, 2nd Edition, Springer, 1983 • Niemann, G., Winter, H., Elementi di Macchine, Edizioni di Scienza e Tecnica, 1986 • Niemann, G., Winter, H., Höhn, B., Manuale degli organi delle macchine, Tecniche Nuove, Milano, 2006 • Giovannozzi, R., Costruzione di Macchine, vol. 1 & 2, Patron, 1980 (historical) • Pighini, U., Elementi Costruttivi delle Macchine, Edizioni Scientifiche Associate, 1980 (historical) • Strozzi, R., Lezioni di Costruzione di Macchine, Pitagora, Bologna, 1998

Modalità di esame: Prova scritta (in aula); Prova orale obbligatoria;

Exam: Written test; Compulsory oral exam;

... Exam: Written test; ; Compulsory oral exam: written theoretical exam. It is expected that the student achieves specific skills such as: To perform preliminary verification and dimensioning calculations on the main machine components, with the aid of tables, diagrams and formulas from technical codes and standards; To know the theory related to the aspects analysed during the course. The final exam consists of two parts referring respectively to the Written exercise exam Part and Written theory exam Part. Both part are performed in presence with a written exam. The written exam can be followed, on request of the teacher, by an oral examination to clarify doubts about the written exam. Dates and classrooms for the Written exam will be indicated in the educational portal. The two written exam can be sustained in a single date or in two separate dates, depending on the availability. To be admitted to any part of the exam, it is required to have and to show a valid identification card or the personal university card with a clearly readable photograph. In absence of this evidence the candidate will be rejected and the attendance to the test forbidden. The use of any electronic digital device (phones, smartphones, tablets, computers, etc.) except calculators (even programmable, but without any operating system) is strictly forbidden. The use of any of these digital electronic devices will be subjected to cancellation of the test. Only the material expressely authorized by the teachers and their assistants can be used, except for paper, pens and pencils, rubbers and correctors, rulers and other measuring and drawing aids and calculators. The use of any types of written or typed papers, books or handbooks is not admitted and is a reason for immediately excluding the student from the examination. It is not permitted to communicate in any form with other students or with any other person except the teachers and their assistants. Any transgression will be subjected to expulsion and exclusion from the exam. Admission to the exams follows registration to the call in the dates indicated in the portal. Exam topics: • Written exercise Part (duration 2 hours): it consits in 3 exercises of Machine Design to be numerically solved; exercises will be like the ones solved during practice. Correct numerical results are mandatory: development of the calculations is not sufficient for a positive outcome, as well as erroneous numerical results. Each of the three exercises can be rated to a different score depending on its complexity, the total score that can be achieved from the three exercise is 30 (given by the sum of the individual scores). This score is referred to the part of Machine Design exercise and is called A. • Written Theory Part (duration 1 hour): o 3 open questions on general topics of Machine Design where it is requested to describe a topic included in the course by developing the answer in the most concise way using formulas, drawings, diagrams which are pertaining to the question for a complete representation of the answer. Each of the three questions is rated from 0 to 10 for a maximum total score of 30. Both tests (exercise and theoryt) must be taken in the same session. To be admitted to the exam it is mandatory to deliver the Homeworkproject in the scheduled time, and to achive a postive evaluation of it. To complete the exam, the student has to pass both the Exercise Machine Design part (A) and Theory Machine Design part (B) with a sufficient score equal or higher than 18, i.e., A>=18 and B>=18. If both tests will be evaluated sufficient, final score will be computed as a average between the marks of the two parts, plus additional points from the evaluated homework technical project. First of all, the teachers will evaluate the outcome of the homework project that is reported in the technical report, and can reject it if it is considered not acceptable: in this case the exam will not be recorded, even in the case of a positive result, and must be repeated until an acceptable report is resent within the same date of the written exam and rated. A technical report is considered unacceptable if it completely lacks of one of the requested sections. If the technical report is considered acceptable, the range of points assigned to the report goes from -3 to +3, and it is referred as score "C". 1 point is subtracted if the team did not report all the diagrams that are requested on the technical report. 1 point is subtracted for the lack of details on each diagram (lack of scale, axes, legends, correct dimensions and units, clarity) presented in the homework technical report. Note that the report shall be delivered before the beginning of the Examination session where the student decided to take exam. Failure to comply with this deadline will prevent participation to the following session exam. Delivery of the technical report will be fulfilled in electronic form according to specifications that will be detailed during the course. THE FINAL SCORE WILL BE DETERMINED AS FOLLOWS: 1) Written test - Exercise (A score) - Machine Design Exercises (3) = max 30/30 2) Written test- theory (B score) - Machine Design Questions (3) = max 30/30 3) Technical report and drawings = max 3 points (= C) NOTE: Both A and B are requested to be>18, for a positive exam. Final score = (A+B)/2 + C An oral exam can be requested by the teacher in case of doubt/problems during the exam. If the Oral exam is requested this becomes mandatory.

Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.

Modalità di esame: Prova scritta tramite PC con l'utilizzo della piattaforma di ateneo;

Exam: Written test; Written test; Compulsory oral exam; Compulsory oral exam; It is expected that the student achieves specific skills such as: To perform preliminary verification and dimensioning calculations on the main machine components, with the aid of tables, diagrams and formulas from technical codes and standards; To know the theory related to the aspects analysed during the course. The final exam consists of two parts referring respectively to the Written exercise exam Part and Written theory exam Part. Both part are performed using the exam tool (respundus). The written exam can be followed, on request of the teacher, by an oral examination to clarify doubts about the written exam. Dates and classrooms for the Written exam will be indicated in the educational portal. The two written exam can be sustained in a single date or in two separate dates, depending on the availability. To be admitted to any part of the exam, it is required to have and to show a valid identification card or the personal university card with a clearly readable photograph. In absence of this evidence the candidate will be rejected and the attendance to the test forbidden. The use of any electronic digital device (phones, smartphones, tablets, computers, etc.) except calculators (even programmable, but without any operating system) is strictly forbidden. The use of any of these digital electronic devices will be subjected to cancellation of the test. Only the material expressely authorized by the teachers and their assistants can be used, except for paper, pens and pencils, rubbers and correctors, rulers and other measuring and drawing aids and calculators. The use of any types of written or typed papers, books or handbooks is not admitted and is a reason for immediately excluding the student from the examination. It is not permitted to communicate in any form with other students or with any other person except the teachers and their assistants. Any transgression will be subjected to expulsion and exclusion from the exam. Admission to the exams follows registration to the call in the dates indicated in the portal. Exam topics: • Written exercise Part (duration 2 hours): it consits in 3 exercises of Machine Design to be numerically solved; exercises will be like the ones solved during practice. Correct numerical results are mandatory: development of the calculations is not sufficient for a positive outcome, as well as erroneous numerical results. Each of the three exercises can be rated to a different score depending on its complexity, the total score that can be achieved from the three exercise is 30 (given by the sum of the individual scores). This score is referred to the part of Machine Design exercise and is called A. • Written Theory Part (duration 1 hour): o 3 open questions on general topics of Machine Design where it is requested to describe a topic included in the course by developing the answer in the most concise way using formulas, drawings, diagrams which are pertaining to the question for a complete representation of the answer. Each of the three questions is rated from 0 to 10 for a maximum total score of 30. Both tests (exercise and theoryt) must be taken in the same session. To be admitted to the exam it is mandatory to deliver the Homeworkproject in the scheduled time, and to achive a postive evaluation of it. To complete the exam, the student has to pass both the Exercise Machine Design part (A) and Theory Machine Design part (B) with a sufficient score equal or higher than 18, i.e., A>=18 and B>=18. If both tests will be evaluated sufficient, final score will be computed as a average between the marks of the two parts, plus additional points from the evaluated homework technical project. First of all, the teachers will evaluate the outcome of the homework project that is reported in the technical report, and can reject it if it is considered not acceptable: in this case the exam will not be recorded, even in the case of a positive result, and must be repeated until an acceptable report is resent within the same date of the written exam and rated. A technical report is considered unacceptable if it completely lacks of one of the requested sections. If the technical report is considered acceptable, the range of points assigned to the report goes from -3 to +3, and it is referred as score "C". 1 point is subtracted if the team did not report all the diagrams that are requested on the technical report. 1 point is subtracted for the lack of details on each diagram (lack of scale, axes, legends, correct dimensions and units, clarity) presented in the homework technical report. Note that the report shall be delivered before the beginning of the Examination session where the student decided to take exam. Failure to comply with this deadline will prevent participation to the following session exam. Delivery of the technical report will be fulfilled in electronic form according to specifications that will be detailed during the course. THE FINAL SCORE WILL BE DETERMINED AS FOLLOWS: 1) Written test - Exercise (A score) - Machine Design Exercises (3) = max 30/30 2) Written test- theory (B score) - Machine Design Questions (3) = max 30/30 3) Technical report and drawings = max 3 points (= C) NOTE: Both A and B are requested to be>18, for a positive exam. Final score = (A+B)/2 + C An oral exam can be requested by the teacher in case of doubt/problems during the exam. If the Oral exam is requested this becomes mandatory.

Modalità di esame: Prova scritta (in aula); Prova scritta tramite PC con l'utilizzo della piattaforma di ateneo;

In case of the mixed exam method, the exam will be organized in the same way as in the remote exam, but the students will sustain it in presence on a room and will use paper to anwer to the questions.