The course intends to give the basic knowledge about the stress analysis of mechanical components, the mechanical behavior of materials under different operating conditions, and the correspondent failure criteria. At the end of the course, the student will be able to carry out the structural mechanical design and the structural analysis of mechanical components and systems.
The course deals with the problems of the stress and strain determination in the mechanical components, the materials mechanical behaviour, the strength criteria under the action of static or cyclic loads. Such concepts are applied to the structural analysis and strength assessment of the most common machine elements.
Recalls on stresses and strains in continuous deformable bodies.
Mechanical behaviour of materials and strength assessment under static loads.
Material charecterisation tests: tension, compression, torsion. Strength criteria for ductile and brittle behaviour, safety factor, probabilistic approach.
Notch effects
Stress concentration, notch design, plastic deformation and residual stresses
Mechanical behaviour of materials and strength assessment under cyclic loads.
Evolution of the fatigue damage and fatigue limit, influence of mean stresses, notches, dimensions, surface finishing, load frequency and waveform. Fatigue strength criteria for uniaxial and multiaxial stress states.
Miner law, random fatigue. Contact fatigue. Fatigue design: material selection, influence of thermal and mechanical treatments on the fatigue resistance of the mechanical components, notch design
Design and strength verification of typical machine components.
Welded and bolted joints, shafts, bearings, cranks and crankshafts, gears and speed reducers, pressure vessels.
De Paulis, Manfredi, Costruzione di Macchine, Criteri di base ed applicazioni principali, Pearson, 2019
Donzella G., Gretter S., Appunti di Costruzione di Macchine, Cartolibreria Snoopy edizioni, 2018.
Donzella G., Mazzù A., Petrogalli C., Costruzione di Macchine, Richiami teorici ed applicazioni, Parte 1: Problemi statici, Cartolibreria Snoopy edizioni, 2018.
Donzella G., Mazzù A., Petrogalli C., Costruzione di Macchine, Richiami teorici ed applicazioni, Parte 2: Fatica, Cartolibreria Snoopy edizioni, 2018.
For more details:
Belloni, Lo Conte, Costruzione di Macchine, Hoepli, 2002
Shigley J.E., Mischke C.R., Budynas R.G., Progetto e costruzione di macchine, McGraw-Hill, 2014 (third edition)
Theoretical lessons and numerical exercises
Evaluation is based on a written test and an oral examination.
The written test aims to verify the knowledge and skills of the student to carry out the structural and failure analysis of a mechanical component or structure in an autonomous and numerical way. The evaluation of the written test is made in thirtieths and the achievement of the score of 18/30 is a necessary condition for the access to the next oral exam.
The oral exam completes the student's assessment, allowing to verify more in detail the theoretical knowledge and its critical spirit.
The evaluation of the oral test can determine a change in the score acquired in the written test, typically of the maximum order of 3-4 thirtieths or, in the event of a negative outcome, the failure to pass the entire exam.
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