2023-2024 / MECA0001-2

Mechanics of materials


27h Th, 25h Pr, 2h Labo., 12h Proj.

Number of credits

 Bachelor of Science (BSc) in Architectural Engineering5 crédits 
 Bachelor of Science (BSc) in Engineering5 crédits 
 Master of Science (MSc) in Aerospace Engineering5 crédits 
 Master of Science (MSc) in Geological and Mining Engineering5 crédits 


Jean-François Demonceau, Laurent Duchene

Language(s) of instruction

French language

Organisation and examination

Teaching in the first semester, review in January


Schedule online

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

Overview and structure of the course

  • Genaral equilibrium principles (identification of all external efforts acting on the studied body, concept of the cut and identification of the internal forces acting on both sides of the cut)
  • Notions of stresses and of plasticity surfaces (Mohr circle in in-plane stress field)
  • Material properties: link between the stresses and the deformations
  • Beam definition
  • Calculation of internal forces in a structure constituted of beams (MNT diagrams)
  • Calculation of internal forces in a truss
  • Security concepts
  • Study of the different internal forces in a beam section - how to pass from internal forces (MNT) to stresses (axial and shear stresses)
  • Deflections in structures made of beams
  • Concept of second order analysis and notions of elastic buckling of beams in compression

Learning outcomes of the learning unit

This course establishes a link between general courses of mathematics, physics and a particular field of the engineering: the mechanics of materials. It strides towards a double objective:

  • to teach the students how to make use of notions studied in these general courses in broaching a new subject, implying to "mix" these notions and to develop the aptitude of synthesis and application;
  • to give to the students the basics in Material Mechanics and to teach them how to apply these ones to some practical cases of beams.
For engineering students who shall specialize in civil engineering, architecture, mechanics, applied physics, this course will be of basic use for series of more specialized courses, such as mechanics of solids, theory of structures, knowledge of materials, ... It will enable them to integrate the notions of equilibrium and stress on the actual and unidimensional case of beams before studying applications requiring the use of full tensors in the course of Solid Mechanics.

For the others, this course is an education to scientific approach for engineers, while providing basic terminology that will be useful for discussions with specialists.

After the courses, the student should be able, for structures made of beams and for a given loading situation, to achieve the following tasks:

  • Draw the MNT diagrams in the structure
  • Achieve adequate cuts in the structure and evaluate the corresponding internal forces
  • From these internal forces, to calculate the stresses in the cross-section
  • Define whether or not the constitutive material may resist to the stresses
  • Define how this structure deforms
  • Define whether there is a risk of flexural buckling the the columns
  • Calculate the internal forces in a truss structure
This course contributes to the learning outcomes I.2, II.1, II.2, III.1, III.2, VII.2, VII.4 of the BSc in engineering.

Prerequisite knowledge and skills

Course of « Physique Générale », of « Analyse Mathématique» and of « Algèbre »

Planned learning activities and teaching methods

Classical organisation

  • Lectures are ex-cathedra courses. They are taught in French but the PowerPoint presentations are in English (2 hours per week). Time for questions is allowed especially after each lesson or during breaks.
  • Mandatory sessions for exercises (2 hours per week); the latter are solved, explained and commented by student-instructors. The active participation of students is hightly recommanded during exercises sessions. These exercises sessions are given in French.
  • Complementary exercises proposed to the students, for students to train themselves to solving exercises (in the specific exercise book of the course and in the specific booklet for the exercises - final answers are given)
  • home-made assignments (compulsory): resolution of exercices representative of what the student should be able to do at the end of the course. Final solutions are provided after submission.
  • 3 special sessions for questions and answers (optional). A team of students-instructors together with an assistant and the professors is in a classroom for 1 hour to answer the questions of the students. The schedule and classes for these sessions are provided via eCampus
  • A mandatory visit to the laboratory session (compulsory - 1 1/2 hour); some of the taught principles will be illustrated.

Mode of delivery (face to face, distance learning, hybrid learning)

Face-to-face course

Additional information:

Classical organisation

  • Face-to-face lectures
  • Compulsory participation in exercise sessions where application examples are handled by student monitors

Recommended or required readings


  • Photocopies of the book " "Mécanique des Matériaux » (S. Cescotto) (available by CdC, "Centrale des Cours")
  • The two first chapters of the book for the courses of "Mécanique du Solide" (/!\ the engineers-architects and the civil engineers in the Construction and Mechanics options, need the whole book of "Mécanique du Solide" taught in the second semester) (available by CdC, "Centrale des Cours")
  • The slides presented during the courses are made available on eCampus, as far as possible before the theoretical courses

  • Book of exercises (available by CdC, "Centrale des Cours")
  • The two first chapters of the book for the courses of "Mécanique du Solide" (/!\ the engineers-architects and the civil engineers in the Construction and Mechanics options, need the whole book of "Mécanique du Solide" taught in the second semester) (available by CdC, "Centrale des Cours")
  • A specific booklet containing the main theoretical aspects required to solve the exercises; it is made available on eCampus
  • A collection of solved exercises, available on eCampus
  • Short videos uploaded through eCampus to help the students to start exercises.

Exam(s) in session

Any session

- In-person

written exam ( open-ended questions )

Additional information:

  • Two homeworks (in French)
  • Written exam (in French): open questions on theory (1 hour) and solution of problems (3 hours)
Authorized tools during exams:

  • theory : none
  • exercises : all notes

The homeworks are inseparable from the teaching unit and considered mandatory.

In the first session the following distribution is classically applied:

- 15% for the homeworks

- 35% for the "theory" part of the exam (open questions)

- 50% for the "exercises" part of the exam

In the second session, the homework grade is taken into account if it is favorable to the student; the distribution adopted is then identical to that of the first session. Otherwise, the following new distribution applies:

- 41.2 % for the "theory" part of the exam (open questions)

- 58.8 % for the "exercises" part of the exam

Work placement(s)

Organisational remarks and main changes to the course

Courses and sessions of exercises are organised on the Sart-Tilman campus, except for the first course which will take place at "Liege Center - Opera" (Auditorium 02 - Lejeune). All informations are communicated through eCampus. To have access, students should have validated their study program.

For the courses : Wednesday, from 08h00 to 10h00 with a break: auditorium B4 A304 (0/30) [Liège Sart-Tilman - Agora]. See "organisation cours et TP" on eCampus where some modifications couldpossibly be announced.

For the sessions of exercises: Wednesday, from 10h30 to 12h30: see "organisation cours et TP" on eCampus.



  • Teachers: Laurent Duchêne, Professor (phone: 04/366 93 28; l.duchene@uliege.be) et Jean-François Demonceau, Associate Professor (tel: 04/366 93 58; jfdemonceau@uliege.be)
  • Secretary: Laurence Defrère ; phone: 04 366 93 57
  • Assistants : Loris Saufnay (office: bâtiment B52, +1/537; phone: 04/366 92 97; loris.saufnay@uliege.be) et Calogero Gallo (office: bâtiment B52, +1/446; phone: 04/366 98 35; cgallo@uliege.be)
- The assistants are available to answer the questions of the students concerning the course and the organization of the latter. Do not hesitate to make an appointment by email to ask your questions.
- The assistants will as much as possible answer the questions sent by email, knowing that it is always better and easier to make an appointment and discuss orally of your questions.

- The assistants will no longer answer questions concerning the course during the last 2 days before an exam or the submission of a report.

  • Students-instructors:
Robin Moise (r.moise@student.uliege.be)

Camille Chevalier (C.Chevalier@student.uliege.be)

Benjamin Keutgen (Benjamin.Keutgen@student.uliege.be)

François Braibant (francois.braibant@student.uliege.be)

Antoine Mouchamps (antoine.mouchamps@student.uliege.be)

François Bustin (francois.bustin@student.uliege.be)


Association of one or more MOOCs