Learning objectives
Knowledge and understanding
The course, which is configured as a natural continuation of the course of Structural Mechanics, aims to improve the basic structural skills of students.
In particular, the course is intended to:
- complete the study of structural models introduced in the Course of Structural Mechanics
- study the mechanical behavior of materials and their response in presence of cracks
- study the mechanical behavior of materials and their response in presence of cracks propagation due to cyclic loading.
Applying knowledge and understanding
At the end of the Course, each student should be able to model one-dimensional structures (cables) and two-dimensional structures and to determine their equilibrium conditions, and to be able to assess the safety with respect to the fracture failure of civil, mechanical, aeronautical structures.
Communication skills
At the end of the Course, each student should know all the technical words related to the topics treated.
Prerequisites
Structural Mechanics
Course unit content
The topics treated in the Course are the following ones:
(1) Static response of cables
(2) The influence lines for statically determinate elastic frames (beam systems)
(3) Plane stress and plane strain states
(4) Fracture failure
(5) Strength criteria under cyclic loading
Full programme
(1) Static response of cables
- Introduction
- Cables under significant tension
- Cables under low tension
- Exercises
(2) The influence lines for statically determinate elastic frames (beam systems)
- Fundamentals
- Use of the influence lines
- Exercises
(3) Plane stress and plane strain states
Plane stress state
- Formulation: Stress function or Airy function
- Simple cases related to rectangular plates
- Cantilever beam with a rectangular cross section
- Supported beam with a rectangular cross section
Plane strain state
- Formulation
Plane stress and stain state for solids of revolution
- Formulation
- Thick cylindrical vessel
- Circular hole in a plate subjected to tension
- Concentrated force acting on the edge of an elastic half-plane
(4) Fracture failure: fracture mechanics concepts
- Energy-based Griffith criterion and fracture energy
- Stress-based Westergaard method
- Correlation between fracture energy and the critical value of the stress intensity factor
(5) Fatigue phenomena
- Experimental approach and analytical approach
Bibliography
Recommended books:
- O.Belluzzi “Scienza delle Costruzioni” Vol.I e Vol.III, Zanichelli, Bologna.
- E. Viola, “Esercitazioni di Scienza delle Costruzioni – Vol.1: Strutture isostatiche e geometria delle masse”, Pitagora Ed., Bologna
- A. Carpinteri, “Scienza delle Costruzioni” Vol.2, Pitagora Ed., Bologna
- A. Carpinteri, “Meccanica dei materiali e della frattura”, Pitagora Ed., Bologna
All books are available by the library (Biblioteca Politecnica di Ingegneria e Architettura).
Additional educational material:
- Documentation provided by the teacher (Centro Documentazione - Ingegneria – Sede Didattica)
Teaching methods
The Course consists of theoretical lectures and practical tutorials. For each topic treated in the Course, exercises are solved so that each student can determine the solutions of the theoretical problems explained just before such practical tutorials.
The theoretical lectures are delivered by employing transparencies, which the students can get at the Documentation Office.
For each theoretical topic treated, practical tutorials are planned according to two modes:
- at first, by employing transparencies (which the students can get at the Documentation Office) to explain the solution methods;
- then, students solve some exercises in the lecture hall, and a common discussion on the difficulties to solve them follows.
Assessment methods and criteria
The final test of the Course of Laboratory of Structures (Structural Mechanics) consists of a oral test which is weighted as follows:
Oral test:
- 70% application of theoretical concepts to practical cases, i.e. exercises (applying knowledge and understanding)
- 20% questions on theoretical concepts (knowledge and understanding)
- 10% ability to present scientific topics with the right technical words (communication skill)
Other information
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