- Docente: Dario Croccolo
- Credits: 6
- SSD: ING-IND/14
- Language: Italian
- Teaching Mode: Traditional lectures
- Campus: Forli
-
Corso:
First cycle degree programme (L) in
Mechanical Engineering (cod. 0949)
Also valid for First cycle degree programme (L) in Aerospace Engineering (cod. 8263)
First cycle degree programme (L) in Aerospace Engineering (cod. 8263)
Learning outcomes
The outcomes of the course are to
provide the basic knowledge, the methods and the tools useful for
the correct definition of the mechanical design activities. At the
end of the course the students will be able to reproduce the
representation of a simple mechanical system, to define the
relationship between the elements, to calculate the constraints, to
draw the stress diagrams and to compute the maximum tensile state
of the components. Furthermore they will be able to verify the
fatigue life of simple mechanical components and to calculate the
strength of some basic bolted and welted structures. Finally they
will be able to select the most appropriate rolling bearings to be
positioned as constraints of shafts, pins and
axes.
Course contents
Introduction to the study and to the analysis of a mechanical system.
Function analysis of a product; the kinematics and dynamic representation of a simple mechanical system and the relationships between the machine elements.
The rigid body equilibrium.
Work and power. Motion and energy transmission between the machine elements. Morphologic characteristics and the load analysis of the mechanical systems. Structural models and tensile state analysis. Stress concentration factors. Residual stresses. The normal stress. The bending stress. The shear stress. The torsion stress. The failure of materials under static loads. The equivalent uniaxial stress in case of static load.
The dynamic failure of the metals. The fatigue stress. The S-N (Wlöer) curves and the Haigh diagrams. The surface, gradient, dimension and load effects on the fatigue strength. The equivalent uniaxial stress in case of dynamic load. The medium stress effects on the fatigue strength.
The gear design. The tooth stress: the bending and the pitting strength. The cylindrical gears straight-toothed and helical-toothed. The conical gears. The loads produced by the gears on the shafts.
Fundamentals of bolted and welded structures: the static calculation.
The rolling bearings selection and their life prediction.
Readings/Bibliography
Texts references
Dario Croccolo, Nicolò Vincenzi - Lezioni di fondamenti e tecnica della progettazione meccanica -Esculapio (Progetto Leonardo) Bologna
Dario Croccolo, Rossano Cuppini-Esercizi di Tecnica delle Costruzioni meccaniche e Costruzione di Macchine-Pitagora Editrice Bologna
Recommended reading
R. Giovannozzi
“Costruzione di macchine” vol I e II
Patron, Bologna
Niemann/Winter
“Elementi di macchine” vol I
EST Springer–Verlag Berlin, Heidelberg, New York
Teaching methods
The lectures concern the fundamentals problems of the mechanical design of products and systems. The practising are collective and concern the application and practical solutions of theoretical problems proposed during the lectures.
Assessment methods
The exam consists in a written part and in an oral one. The written part consists in three exercises to be solved in which both the conceptual and the numerical results will be evaluated. The oral part consists in a discussion about the written part and about the theoretical arguments dealt during the lectures.
Teaching tools
PC projector, Overhead projector, blackboard
Office hours
See the website of Dario Croccolo