2017-2018 / MECA0502-1

Mechanics of composites

Duration

30h Th, 30h Pr

Number of credits

 Master in aerospace engineering, professional focus in turbomachinery aeromechanics (THRUST) (Erasmus mundus)5 crédits 
 Master in aerospace engineering (120 ECTS)5 crédits 
 Master in mechanical engineering (120 ECTS)5 crédits 

Lecturer

Michaël Bruyneel

Language(s) of instruction

English language

Organisation and examination

Teaching in the first semester, review in January

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

The course introduces different aspects of fibre-reinforced plastic materials :
- overall description : constituents, matrix and fiber architecture, industrial applications (aerospace, automotive, energy), links between process, microstructure, material properties and structural performance.
- mechanical properties : linear elasticity of orthotropic (and anisotropic) materials, classical laminate theory (CLT), progressive damage and failure mechanisms, edge effects, humidity and temperature effects.
- homogenization : principles, mean-field homogenization applied to linear elasticity, extension to elastoplasticity, applications to short and continuous fibre-reinforced plastics.
- numerical simulation : linear and nonlinear finite element analysis (buckling, post-buckling, collapse, nonlinear material).
- design of composite structures : design rules and manufacturing constraints, parameterizations and optimization algorithms, stacking sequence optimization.

Learning outcomes of the learning unit

At the end of the course, students should have acquired the following knowledge and skills :
- an overview of the different kinds of composites and their constituents;
- linear and nonlinear mechanical characteristics of continuous fiber laminates, including damage and failure mechanisms ;
- homogenization techniques and basis multi-scale material modeling ;
- Integrated Computational Mechanical/Material Engineering (ICME): Integration of process, material and structural modeling.
- the classical laminate theory ;
- main design rules and stacking sequence optimization of composite laminates;
- a theoretical knowledge of manufacturing process and related constraints;
- the ability to analyse a composite structure with industrial finite element software.

Prerequisite knowledge and skills

A background in continuum mechanics and finite element methods is required.

Planned learning activities and teaching methods

Theoretical concepts are explained during formal lectures and seminars. All speakers have a strong industrial background and share their practical experience with students. Exercise sessions are meant to put the classical laminate theory into practice (analysis of continuous fiber laminate properties with analytically calculated ABD matrices). Students have individual graded projects involving SAMCEF finite element software and Digimat, which are introduced during computer sessions.

Mode of delivery (face-to-face ; distance-learning)

Theoretical lectures are taught in class by the professor. Exercise sessions are led by the assistants. Mandatory practical sessions are organized in a computer room where numerical simulation tools are available.

Recommended or required readings

References :
Lecture notes (contact M. Bruyneel)
Strength and life of composites, S.W. Tsai, ed. JEC Composites Publication: homogenization, orthotropy, CLT, failure theories.
Matériaux composites, D. Gay, ed. Hermes, Paris, 2005: homogenization, orthotropy, CLT, failure theories, lots of applications.
Composite airframe structures, M.C.Y. Niu, ed. Conmilit Press LTd. Hong Kong, 1992: testing, manufacturing, applications.
Optimisation des structures mécaniques: méthodes numériques et éléments finis, M. Bruyneel, J.C. Craveur, P. Gourmelen, ed. Dunod, Paris, 2014 : composite materials

Assessment methods and criteria

Written exam, theory (closed-book): 50% of the total points
Written exam, exercises (open book): 25% of the total points
Practical work on computer reports: 25% of the total points
 

Work placement(s)

Organizational remarks

Contacts

Michaël Bruyneel (Michael.Bruyneel@ulg.ac.be
Martin Volvert (m.volvert@ulg.ac.be)(geoffrey.deliege@ulg.ac.be)

Michaël Bruyneel (Michael.Bruyneel@ulg.ac.be
Martin Volvert (m.volvert@ulg.ac.be)(geoffrey.deliege@ulg.ac.be)

Items online

Exam 2016 - Exercises
Exam 2016 - Exercises

Mechanics of Composites: Exercises
Dear all,

Here is the statements of the exercise session 1-4.

Session 3 - More information
Dear all,

For the exercise session 3, here are the graphs from the last exercise.

furthermore, some of you asked some more details about the use of the maximum strain criterion used for exercise 1. Here are some more details about the use of the maximum strain in tension OR in compression. You need to check the sign of your epsilon_x, epsilon_y and epsilon_s to see if you are in compression or traction and then use the correct criterion. Plus, I made a mistake in the notation for N^{FPF}. See the following file to check it for a complete understanding.