70/LM-0039 - FUNDAMENTALS OF MACHINE DESIGN
Academic Year 2020/2021
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BRUNO LEBAN (Tit.)
- Teaching style
- Lingua Insegnamento
|[70/88] CHEMICAL AND BIOTECHNOLOGICAL PROCESS ENGINEERING||[88/00 - Ord. 2020] PERCORSO COMUNE||6||60|
The course is aimed at students of the 3rd academic year of Chemical Engineering who have already attended and passed the courses "Industrial Design" and "Fundamentals of Machine Design" and has as its goal the understanding of the main issues related to the sizing and problems in operation of mechanical components.
Aim of the course is also the acquisition of the ability to schematize and quantize structural problems: in this sense the course of Fondamenti di Progettazione provides the basic tools for the treatment of large classes of problems.
Issues related to the exercise of mechanical components, with particular reference to axes and trees will be addressed, illustrating the problems of static and dynamic strength, fatigue, ductile and brittle materials, without neglecting the problems of wear.
The student will acquire the foundation needed to address the engineering problems by applying, as far as possible, the scientific knowledge acquired in previous courses.
Knowledge and understanding
- Major structural problems related to the exercise of mechanical components
- Identify the most dangerous working conditions
- Perform a critical analysis of the structural solution
- Understanding the reasons who determined the achieved solutions
- Analyze technical documents on the topics of the course
- Express the result of calculations in the form of a technical report
The student will be able to critically analyze the various solutions.
Being able to fully illustrate by sketches, calculations, text, the problems inherent in the various structural solutions.
The student should know the contents of the modules listed in the objectives, with particular reference to the course "Fondamenti di Costruzioni di Macchine". The correct identification of stress states are absolutely essential.
Faced with the study of the problems inherent in the operation of machine components in service, the student must also have an accurate picture of the scope in which they are to be inserted, so the knowledge about the courses of "Applied Mechanics" and of "Manufacturing Technology" are prerequisites for the proper schematization of loads and the technological limits.A good knowledge of the way in which these concepts are described, alongside the issues related to manufacturing tolerances (provided by the Design course) is also highly desirable.
Introduction to Mechanical Design
Notes on the analysis of loads in structural testing.
Properties of cast iron, steel, other metal alloys, plastics, composites.
Stress states: Tension, compression, bending, shear and torsion. Complex states.
Mohr circles (stress and strains)
Concepts of stiffness and stability
Virtual work principle, Müller-Breslau equations.
Euler's formula for elastic instability of beams; Johnson's parabolic formula.
Linear elastic fracture mechanics.
Yield of components: maximum normal stress, maximum shear stress, maximum energy of distortion, Mohr-Coulomb and modified Mohr approach.
Safety and reliability. Notes on probabilistic design.
Hight and low cycle Fatigue: principal factors affecting life,
Complex states of stress, cumulative damage.
Corrosion, Stress corrosion cracking, Fatigue and corrosion.
Adhesive and abrasive wear; fretting. Contact problems. Surface fatigue.
The course consists of lectures and exercises. As soon as enough knowledge are available, exercises focusing on the problems resulting from dimensioning and testing the analyzed components are proposed. Exercises are framed in the context of real problems trying to provide quantitative values of the involved parameters. From a temporal point of view, the distribution Lessons / exercises is about 70 and 30% of the total of the course.
Verification of learning
The examination consists of a written and an oral test. In the former, problems similar to those faced in the course will be proposed. The candidate will have to correctly identify loads and constraints of the system and perform an initial sizing of components.
The oral test focuses on the topics of the course; more in detailed it focuses on the verification of the concepts and issues involved in sizing and monitoring of the mechanical components.
R.C. Juvinal, K.M.Marshek - "Fundamentals of Machine Components Design", Wiley
J.E. Shigley, R.G. Budynas, J.K. Nisbett, " Shigley’s Mechanichal Engineering Design". McGraw-Hill
Exercises and didactic materials will be available on the official webpage.