34313 - Machine Design

Learning outcomes

Fundamentals in solid mechanics, structural anaylsis and related normative references. Stress and strain analysis and mechanical behaviour of materials due to static, fatigue and thermal loading. Basic design practices of shells and plates.

Course contents

Part 1 (solid mechanics): quasi-static tensile test, stress and strain tensor, mechanical behavior of materials and Hooke's law, elastic strain energy density, thermal effect. Transformation of the stress tensor, principal stress components and representation of the stress state in Mohr's plan. Strength criteria. Indefinite equations of equilibrium, compatibility and constitutive relationships. Existence and uniqueness of the solution.
Part 2 (pressure vessels): dimensioning, strength verification and strain calculation of thick cylindrical and spherical reactors. Design and verification of cylindrical and conical shells, spherical, torispherical and ellipsoidal dished ends.
Part 3 (static analysis of beam systems): structural analysis of frames and trusses labile, iso- and hyper-static. Analysis of the loads and constraints, modelling of the balanced load pattern in the free body, diagrams of the internal actions. Geometric properties of plane sections (area, static moments and moments of inertia, inertia tensor, principal inertia and representation in the Mohr's plane). Stress and strain analysis of axial force, torsion, bending and shear. Study of the elastic line of beams in bending, elastic influence coefficients. Buckling of compressed beams.
Part4 (machine elements): stress field due to Hertzian contact, bearings, spur gears.
Part5 (connections): bolted and welded joints.
Part6 (fatigue design): geometric concentration of stresses, fatigue and fracture mechanics, creep, residual stresses, welding.

 

Readings/Bibliography

Technical handbook (course specific):

P. Morelli, F. Cesari, 2024. Fondamenti di Meccanica dei Solidi, con Applicazioni e Esercizi. Bologna: CLUEB. ISBN:9788849157659

Handouts and educational integrative materials are available on-line (download link published on the course IOL)

Suggested readings:

Tecnica delle costruzioni meccaniche Vol1 – fondamenti di meccanica e analisi strutturale. V. Fontanari. Città Studi Edizioni.

Meccanica dei solidi. Elementi di Scienza delle Costruzioni. Beer, Johnstone, Mazurek. McGraw-Hill Education.

Meccanica dei solidi e delle strutture. Hibbeler. Pearson.

Scienza delle Costruzioni. Various Authors and editions.

Fondamenti di Costruzione di Macchine. Juvinall, Marshek. Città Studi Edizioni.

Progetto e Costruzione di Macchine. Shigley. McGraw-Hill Education.

Teaching methods

Lecture

Assessment methods

Written examination

Teaching tools

Lecture notes and application examples from the didactic material available on-line.

Use of the symbolic algebraic calculation software WxMaxima.

Office hours

See the website of Piero Morelli