Ing Ind - Inf (Mag.)(ord. 270) - BV (470) SPACE ENGINEERING - INGEGNERIA SPAZIALE
099260 - SPACECRAFT STRUCTURES
The course has the purpose of illustrating the fundamental concepts of structural analysis as applied to aerospace structures. Illustrated are typical models and techniques employed in the design of aircraft and space constructions. The modeling of thin-walled beams and plate-like constructions is discussed along with different solutions strategies for evaluating the linear static response. Due to the relevance of buckling phenomena in aerospace structures, part of the course is devoted to the study of stability of elastic equilibrium for continuous and discrete systems. Aim of the course is to provide a picture of the various problems involved in the analysis and design of aerospace structures, while developing the skills necessary to: perform preliminary analyses of typical aerospace structural configurations using models of increasing complexity; critically choose the methods of analysis; critically assess the quality of the results.
Risultati di apprendimento attesi
After succeeding this course, the student should:
learn the typical configurations of aerospace structures
understand the role played by different structural members
master the theoretical aspects of structural models and classical analysis techniques
and be capable of:
performing preliminary calculations for the linear stress analysis of aerospace structures
developing numerical tools for analyzing the linear response of truss-, beam- and plate-like structures
critically evaluating the adequacy of the analysis tools (structural models and solution strategies) in relation to the problem at hand
critically assessing the results of a structural analysis
1. Aerospace structures
Introduction. Overview of spacecraft and aircraft structures.
2. Continuum mechanics
Lagrangian and Eulerian approach. Stress and strain measures. Equations of balance. Formulation of the elastic problem under small strain and displacement assumptions. Variational principles.
3. Beams in aerospace structures
Review of De Saint Venant solutions for beams.
Monocoque and semi-monocoque schemes. Ribs and frames. Stress along junctions and type of joints.
Kinematic formulations: Euler-Bernoulli and Timoshenko models.
4. Plates and laminates
Kirchhoff and Mindlin plate theories and their extension to composite materials. Evaluation of stresses and strains for isotropic and composite elements. Sandwich structures.
Stability of elastic equilibrium, bifurcations, limit points. Energy approach. Buckling criteria. Approximate and exact solutions for the buckling of beams, plates and shells. Imperfection sensitivity.
6. Solution techniques
Ritz method and residual weighted methods: applications to one- and two-dimensional structures.
The Finite Element Method for the linear structural analysis: stiffness matrix in global and local coordinate systems; loads and boundary conditions; properties of the solution and convergence of the solution.
Lectures and exercise classes.
Calculus I and II, Applied numerical analysis, Fundamentals of structural mechanics.
Modalità di valutazione
The examination consists of two parts:
written test (max grade 30/30)
spoken exam (can be taken if the written test has been passed with a grade greater or equal than 18/30)
The written test consists of:
two exercises on the analysis of truss/beam/plate structures (10 points each)
one open question regarding a theoretical aspect discussed throughout the course (10 points)
The student should be able to solve the exercises by properly setting up the problem, performing numerical calculations and illustrating the choices/assumptions performed throughout the solution of the exercises.
At the spoken exam the student should be able to:
illustrate and critically discuss the topics covered throughout the course
discuss the solution of simple structural problems
illustrate and discuss the Matlab codes developed during the course
The final grade G is obtained as: W-6<G<W+6 where W is the grade of the written test.
V. Giavotto, Strutture Aeronautiche, Editore: CLUP, Anno edizione: 1990
J.N. Reddy, Energy Principles and Variational Methods in Applied Mechanics, Editore: Wiley, Anno edizione: 2002
J.N. Reddy, Mechanics of Laminated Composite Plates and Shells: Theory and Analysis, Editore: CRC Press, Anno edizione: 2004
R. Jones, Buckling of Bars, Plates, and Shells, Editore: Bull Ridge Publishing, Anno edizione: 2006
B.K. Donaldson, Analysis of Aircraft Structures: an Introduction, Editore: Mc Graw Hill, Anno edizione: 1993
K.J. Bathe, Finite Element Procedures, Editore: Prentice Hall, Anno edizione: 1996
L. Corradi Dell'Acqua, Meccanica delle Strutture - Volume 2, Editore: Mc Graw Hill, Anno edizione: 1993
Tipo Forma Didattica
Ore di attività svolte in aula
Ore di studio autonome
Laboratorio Di Progetto
Informazioni in lingua inglese a supporto dell'internazionalizzazione
Insegnamento erogato in lingua
Disponibilità di materiale didattico/slides in lingua inglese
Disponibilità di libri di testo/bibliografia in lingua inglese
Possibilità di sostenere l'esame in lingua inglese
Disponibilità di supporto didattico in lingua inglese