Engineers and analysts are typically asked to perform the design of structures, mechanical components of machines (bolted connections, power transmissions, bearings, shafts, couplings, springs, etc.) and of assembled systems. Nevertheless, two levels of skills can be identified. At basic professional level, machine designers and engineers must be able to analyse an existing machine component and to modify the design to fulfil some given requirements. They are used to apply methods and tools (even software) under the supervision of a senior engineer, by resorting to a typical “design by rule” approach. At standard professional level, machine designers and engineers must be able to perform new designs of machine components and systems, to fulfil specified requirements. They use suitable analytical or numerical methods and are responsible for product liability, as they implement typically the “design by analysis”. Therefore, this module deals with a selection of representative and complementary classes of design problems. Each topic requires a specific development. Students are asked to develop a semester-long Technical Project. It consists of a typical test case of mechanical design, which is analysed in detail. Some design solutions are proposed and compared. In addition, some exercises are proposed to students to be solved and added to the technical report. To develop some useful competences applicable to any kind of mechanical structure or machine, students are required, by the end of this module, to achieve the following targets of knowledge and related capabilities. Knowledge: [A] to know the theory and the experimental approaches, which underpin the mathematical models of mechanical components; [B] to identify the critical weak points for strength, predicting several failure mechanisms; [C] to evaluate uncertainties and to apply appropriate safety coefficients against collapse; [D] to analyse a machine component and check whether it fulfils the standards' requirements; [E] to identify the main design parameters of a component, to define the shape and size of machine elements. [F] to know some typical and theoretical background defined by technical standards; Capabilities and skills: [A] to modify a mechanical design, to improve the system strength and to increase its life or to upgrade specifications; [B] to predict the performance of components assembled into a machine, by investigating their kinematics, loading conditions and stresses, through analytical and numerical methods [C] to identify among several technical solutions those compatible with the available technologies and a suitable layout to convert energy and transmit power; [D] to interpretate mechanical drawings of machine and systems, by identifying parts and components; [E] to impose suitable constraints, to bear mechanical and thermal stresses; [F] to propose suitable assemblies of machine elements to satisfy requirements; [G] to apply mathematical models to component and machine design; [H] to identify and set relevant data needed to design mechanical systems; [I] to approve a design and be able to take responsible decision based on evidence; [J] to validate theoretical or numerical models through some experimental tests; [K] to present, in oral and written formats, a clear and well-structured set of remarks describing the design targets, assumptions and results; [L] to read, understand and analyze technical literature, including handbooks, notes and standards. Those knowledges and capabilities are formed during the course and then checked during the exam, in written and oral tests. They are aligned with the targets defined for the Master Degree in Mechanical Engineering (Modello Informativo SUA-CdS 2022-2023, quadri A4b1 https://didattica.polito.it/pls/portal30/sviluppo.vis_aiq_2013.visualizza?sducds=32053&p_a_acc=2023&tab=sA4b1 e A4b2 https://didattica.polito.it/pls/portal30/sviluppo.vis_aiq_2013.visualizza?sducds=32053&p_a_acc=2023&tab=sA4b2 ). They include the knowledge of design methodologies applied to the main machine elements, with respect to their strength, according to technical standards, and even the capability of effectively working in technical teams composed by several professionals.

To fruitfully attend this course and achieve the proposed targets, students must know: - Standard mathematics for engineers. - Standard physics for engineers. - Basics of strength of material. - Theory of strain and stress tensors, their properties, the Mohr circles. - Elastic properties of materials. - Damage criteria of brittle and ductile materials (maximum normal stress, maximum shear stress or Tresca, maximum distortion energy or Von Mises). - Fundamentals of mechanics, as forces and moments, the dynamics of rigid bodies, the theory of deformable and elastic bodies, the behaviour of bars and beams, under tension, bending, shear and torsion. - A preliminary background of machine elements, technical drawing and of manufacturing systems and technologies. The attendance of this module requires fluent spoken and written English, as a requisite. Lectures, tutorials and didactic material are provided in English.

[1] The design process: methods, goals, activities. Needs, requirements, constraints, innovation targets. Tools and examples of design of systems and machines. Outlines of related standards. Concept, synthesis, verification and validation. Safety and reliability. Functional, operational and architectural requirements. Role of standards, best practices and modelling activity in design. Example of deployment of the whole design process. [2] Fundamentals of machine design: review of applied criteria for static strength of isotropic materials (reading material provided and tutorials) [3] Design against failure: fatigue and fracture (reading material provided and tutorials): - Overview of fatigue problems - Stress-life fatigue: basic material properties and testing on specimen (FKM standards) - Stress-life fatigue: component fatigue, finite and infinite life (FKM standards) - Stress-life fatigue: thermal effects and thermomechanical fatigue, creep and other effects - Crack propagation: linear fracture mechanics, basics, applications, Paris' law - Tutorials: use of the main fatigue diagrams; application of FKM standards; notch effect; application to the Technical project; fracture mechanics: computation of crack propagation and path. [4] Design of assemblies: supports and bearings (reading material provided and tutorials): - Contact mechanics and damage - Rolling bearings: static loading, fatigue conditions - Design of bearing assemblies, main solutions for bearing arrangements - Tutorials: application of Hertz theory on a selection of contact cases; angular contact bearings, preloading diagram; load-life rating of bearings for the Technical Project; bearing assemblies and related problems [5] Design of power transmission: gears (reading material provided and tutorials): - Summary of motion transmission, tooth shape - Spur and helical gears with parallel axes: kinematics, geometry, forces - Cutting techniques and profile displacement - Criteria for strength assessment of gears: fatigue, hertz contact, wear, scuffing - Tutorials: geometry and kinematics of gears, spur gears profile shifting, design of gears of the Technical Project [6] Design of joining systems: bolted connections (reading material provided and tutorials): - Threaded fasteners and connections - Prestressed single bolt connections (without gaskets) - Refinements and special problems - Elements of gasketed bolted connections - Tutorial: selection of exercises - Tutorials: application to a hydraulic piston or to a tie-rod connection [7] Seminars and visits, in collaboration with Companies.

This module provides 8 credits, corresponding to 80 hours, equally divided into 40 of lectures, and 40 of tutorials. The study load for this subject is from 200 to 240 hours, including classes, personal study, completion of tutorials at home and reporting activity. - The lectures describe the theoretical issues of this disciplines and related technical standards as well as their relation with manufacturing processes and technologies. - The tutorials propose several exercises and a more complete project referred to as “Technical Report” dealing with the complete analysis of a mechanical system, representing a real industrial or professional application. Classes are equally shared between lectures and tutorials, to allow students learning by doing, by applying theoretical concepts to some simple examples, exercises and test cases. This module is organised to allow students to gradually develop their knowledge and skills, under the experts' supervision. The whole lectures and tutorials’ material is available on the course website. Students can download and print all the shared material in advance, to add notes during classes. Each section of lectures is almost immediately followed by some specific tutorials. Students are required to apply knowledge to some practical problems, to master the theoretical issues. Each tutor provides the organised material and some frames for solving several proposed exercises. Students are required to solve the proposed tasks themselves, being organized in small groups including three persons. The semester-long project, i.e. the so-called “Technical Report”, is aimed to enhance the problem-solving capabilities of students, and to encourage their independent thinking and to develop professional reporting skills. This Technical Report focuses on the structural analysis of a given mechanical system (different each academic year), including all the main elements of Machine Design. Tutors describe the technical problem object of this analysis, during the tutorials, and show a sort of roadmap to be applied to perform the investigation. Each group of students performs then the structural analysis of a given constructive solution, to check the safety margins applied. Other solutions are even investigated, to propose an optimization of the proposed layout or the selection of more suitable materials and components. In this activity, students apply the theoretical issues learnt during the lectures, implement the rules of technical standards, draw the machine elements to understand in details the system behaviour and architecture, respectively. They are even trained in presenting the whole activity performed. For each task, each group of students produces a final report. The set of all reports will be examined during the final exam. Students are asked to work cooperatively in the small group of three persons already set up to solve the proposed exercises. The tutors assist the groups during the tutorials, supporting students in their learning progression and clarifying their doubts. Attendance to both lectures and tutorials is strongly recommended. This is essential to achieve the expected learning outcomes. The teacher and the tutors are available during the teaching semester, to meet (directly or remotely) students for consultation (please contact them by e-mail to agree about a meeting). Tutorials may benefit from using EXCEL or MATLAB tools. Writing reports with editing software is not required, although a clear and professional presentation is strictly required. Drawing tools (pencil, compass, scale rulers...) are strictly necessary.

Lectures: the subject is fully described by the lectures notes provided by the teacher in the booklet entitled "Machine Design from theory to practice" and then is shown during classes by resorting to a set of slides highlighting the booklet's content. Some additional materials are uploaded on website. Particularly, some sets of slides cover several topics belonging the required background of students (fundamentals of strength of materials and of machine design, taught in the bachelor of science degree in this university). Tutorials: texts of problems, datasheets of materials, extracts or abstracts of standards and handbooks are provided by the tutors. All the lecture materials are available on website, since the beginning of the semester. Students can download and print those files, before the lecture and use the copy to take some notes. Examples of the exams are even provided, during lectures, in all of forms foreseen and depending on the restrictions applied by the pandemic event. Selection of references (just suggested readings, it is never mandatory to buy, but they are cited as a suitable reference): • J. Bickford, Introduction to the design and behavior of bolted joints, CRC Press, 2007 • E. Brusa, Mechatronics: Principles, Technologies and Application, Nova Science, 2015. • E. Brusa, A. Calà, D. Ferretto, Systems Engineering and its application to industrial product development, Springer, 2018. • R. Budynas, Shigley’s mechanical engineering design, McGraw Hill, 2014. • J.E. Carryer, Introduction to mechatronic design, Pearson, 2010. • P.R.N. Childs, Mechanical design engineering handbook, Elsevier, 2014. • G.E. Dieter, L.C. Schmidt, Engineering design, The McGraw-Hill Companies Inc., 2009. • G.E. Dieter, Mechanical Metallurgy, McGraw-Hill, 1988. • T. Harris, M. Kotzaias, Rolling bearing analysis – Essential concepts of bearing technology, CRC, 2006. • E. Kirchner, ‎R. Nordmann, ‎H. Birkhofer, Maschinenelemente und Mechatronik, Shaker Verlag, 2017· • R.C. Juvinall, K.M. Marshek, Fundamentals of machine component design, John Wiley & Sons, 2011 • F. Litvin, Gear geometry and applied theory, Cambridge University Press, 2004. • S. S. Manson, Fatigue and durability of metals at high temperatures, ASM, 2009. • R.L. Mott, E.M. Vavrek, J. Wang, Machine elements in mechanical design, Pearson, 2018. • G. Niemann, Machine Elements Design and Calculation in Mechanical Engineering, Springer Berlin Heidelberg, 1980. • R. Nordmann, Mechatronische Systeme im Maschinenbau, Shaker Verlag, 2005 • M.A. Parameswaran, Mechanical design, a practical insight, Alpha Science Int., 2017. • V. Popov, Contact mechanics and friction, Springer, 2010. • N. Recho, Fracture mechanics and crack growth, ISTE Wiley, 2012. • R. Stephens, A. Fatemi, R. Stephens, H. Fuchs, Metal fatigue in engineering, Wiley,2000. • D. Ullman, The mechanical design process, McGraw-Hill, 4th ed., 2010.

Lecture slides; Lecture notes; Exercises; Exercise with solutions ; Video lectures (previous years); Multimedia materials; Self-assessment tools;

Exam: Written test; Compulsory oral exam; Group project;

Achieved learning outcomes will be assessed by means of a final exam. This is based on an analytical assessment of student achievement of the expected learning outcomes above described. In regular conditions, being not affected by restrictions induced by the health emergency due to pandemia, which recently occurred, the examination is composed by two main sections: written and oral tests. a) Written test (first day of examination): -) a test, 2 hours long, with closed books, no didactic material allowed, is composed by three questions. Two are related to the theoretical issues of lectures (topics are listed above and contents are those of didactic materials shared via website) and verify the knowledge of theory. One exercise completes this test to assess the problem solving skills of students (this is similar to the exercises proposed during tutorials). Each question scores up to 8 marks. To attend the oral exam, the student must score in the written test a minimum of 12 marks, and particularly a minimum of 4 (50%) marks for each question. The maximum score provided by the written test is 24. This test mainly verifies the following knowledges: [A], [B], [C] and the achievement of these capabilities: [B], [D], [G], [H], [J]. b) Oral test (second day of examination, after the written test and score publication) includes: -) a review of written test, to show the student grading criteria and to receive any student's appeal, supported by appropriate explanations (no score for this step); -) a technical conversation with the lecturer, to verify the student's ability to deal responsibly with a mechanical design problem, by identifying an appropriate application of the acquired knowledge, This part is strictly related to contents of theory, explained during the lectures and documented by slides (up to 4 marks) -) a discussion with one tutor, to whom the student will submit the full set of tutorial reports. The tutor will investigate the effective personal achievement of skills and know how, based on contents of reports. This part is strictly related to the activity performed during tutorials, including the development of the Technical report and the solution of the proposed exercises. (up to 4 marks) This oral test mainly verifies the following knowledges: [D], [E], [F] and the achievement of these capabilities: [A], [C], [E], [F], [I], [K], [L]. The final score is composed by the score of written test, added to the score of the two interviews performed during the oral test. The maximum score is 30/30. in case of exceeding result, the teachers will assign the "cum laude".

In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.