Subject: COMPOSITE MATERIALS (A.A. 2024/2025)
Unit Materiali Compositi
To be chosen by the student (lesson)
The course is aimed at giving the basic concepts concerning fiber- and particle-reinforced composites and the calculus of the composite properties by micromechanics and macromechanics approaches.
At the end of the course the student will be able to:
- Know the main properties of matrices and reinforcements.
- Understand the relationships between the properties of the matrix, reinforcement, volume fraction, and the resulting properties of the lamina.
- Predict the behavior of a composite laminate starting from the single lamina.
- Know and apply the resistance criteria.
- Solve numerical problems aimed at the design of composite products.
For a more complete understanding of the course objectives, please refer to the expected learning outcomes reported below.
Basic contents of materials science and engineering:
- structure of matter: amorphous state and crystalline state;
- microstructure of materials;
- elastic and plastic deformations;
- mechanical properties of three classes of materials (polymers, ceramics and metals).
1 CFU (9 hours) - Definition of composite material. Characteristics and fields of application. Notes on the various types of matrix and reinforcements.
1 CFU (9 hours) - Matrix-reinforcement interaction. Volume fraction occupied by the reinforcement. Stress transfer mechanisms (Cox and Kelly-Tyson models).
1 CFU (9 hours) - Prediction of the properties of long fiber composites. Introduction to micromechanics. Mixture rule, inverse rule of mixtures, Halpin-Tsai equations. Prediction of the strength and fracture properties of a long fiber composite.
1 CFU (9 hours) - Prediction of the properties of short fiber composites. Critical length. Prediction of elastic modules: Halpin Tsai equations. Prediction of the strength and fracture properties of a short fiber composite.
1 CFU (9 hours) - Forecast of laminate properties. The unidirectional lamina. The laminates. Failure criteria for an orthotropic lamina: theory of maximum stress, theory of maximum deformation, theory of maximum work. Lamination theory. Outline of manufacturing processes.
1 CFU (9 hours) - Design of composite materials (with numerical exercises).
The course is done according to the following teaching modalities: - Theoretical lectures in the classroom (about 45 hours). - Exercises aimed at the design of composite materials (about 9 hours). Lectures will be in presence. If necessary, the remote delivery of training activities (lessons and exercises) will be guaranteed in synchronous mode with live streaming (for example, on the Microsoft Teams platform). The course is delivered in Italian. Attendance is not compulsory but strongly recommended.
The assessment of the profit (exam) is carried out with the methods and criteria indicated below. - Completion of a final written test (1 hour and 40 minutes) in which the overall learning outcomes acquired by the student are evaluated. - The written test consists of numerical exercises (2, each divided into several parts) and open questions (4). - Oral examination (about 15 minutes). - In assigning the final mark, the level of theoretical knowledge acquired and the ability to apply the knowledge acquired are predominantly assessed. The level of independent judgment and communication skills is also taken into consideration. In particular, the evaluation indicators are: i) ability to use knowledge (65%); ii) ability to connect knowledge (15%); iii) ability to discuss topics (5%); iv) ability to deepen the topics (5%); v) mastery of scientific-technological language (10%). - The final vote is expressed out of thirty, with possible Lode. - Indicatively, the final mark will be the weighted average (90% written test, 10% oral test) of the marks obtained in the written and oral tests. - In case of insufficient marks (less than 18/30) it is necessary to repeat the written test (after at least 15 days).
Knowledge and understanding: Class lesson and exercises to learn how to design a composite component.
Capability of applying the acquired knowledge: With numerical exercises the student will apply the acquired knowledge to determine composite properties.
Autonomy: Designing a composite component will make the student understand and critically evaluate the obtained results
Communication: Class exercises aimed at designing a composite will improve student capabilities of data and results illustration and discussion.
Learning capability: The student will acquire the know- how to keep up to date by himself.
 G. Caligiana, F. Cesari, I materiali compositi, Pitagora Editrice
 I. Crivelli Visconti, G. Caprino, A. Langella, Materiali Compositi, Hoepli
 Barbero, E.J., 1998, Introduction to Composite Materials Design, Taylor and Francis Inc., Philadelphia (PA), USA
 C. Badini, Materiali Compositi per l’Ingegneria, Celid (2013)