Course detail
Continuum Mechanics
FSI-S1K Acad. year: 2027/2028 Winter semester
In this course, students are briefly introduced to the fundamental concepts, laws, and methods for solving specific problems in continuum mechanics, specifically the theory of elasticity, which constitutes a major subfield. The course begins by defining stress and strain at a point within a continuum, along with their properties and the governing laws they must satisfy. This is followed by the formulation of boundary-value problems in elasticity, the proof of the uniqueness of their solutions, and the derivation of its simplified forms, the plane and one-dimensional problems of elasticity. Subsequently, students explore classical methods for solving such plane and one-dimensional boundary-value problems. In the second half of the course, the concepts of energy and work in continuum mechanics are introduced, along with the principle of virtual work and its application to solving elasticity problems via variational methods. This theoretical overview is complemented by worked examples covering one-dimensional and plane elasticity.
Language of instruction
Czech
Number of ECTS credits
4
Supervisor
Entry knowledge
In the field of mechanics: Knowledge of fundamental concepts from elasticity and strength of materials I or II (stress, strain, Hooke’s law).
In the field of mathematics: Ordinary differential equations, partial differential equations, integral calculus, and the fundamentals of the theory of functions of a complex variable.
Rules for evaluation and completion of the course
Examination Requirements:
- maximum/minimum score: 100/50 points,
- written overview test covering fundamental knowledge and concepts (40 points),
- written solution to 2 problems (30 points each),
- oral discussion regarding the written work, potentially including a supplementary question.
Requirements for Course Credit:
- active participation in seminars/exercises,
- satisfactory performance on ongoing assessments of fundamental knowledge,
- completion of make-up assignments in the event of an excused absence.
The specific format for fulfilling these requirements will be determined by the seminar instructor during the first week of the semester. Attendance at seminars is mandatory. Instructors will monitor student attendance, participation, and grasp of fundamental knowledge on an ongoing basis. An unexcused absence is grounds for denial of course credit. A single absence may be compensated for by completing make-up assignments; longer periods of absence require the completion of make-up assignments as directed by the instructor.
Aims
The objective of the course Continuum Mechanics is to introduce students to fundamental concepts, relationships, formulations, and the solution of boundary-value problems in elasticity. In addition to the classical formulation of problems, emphasis is placed on variational formulations, serving as a theoretical foundation for the future application of advanced numerical tools in engineering practice. General elasticity equations and problems are first reduced to two-dimensional plane cases for both isotropic and anisotropic materials, a context historically closely linked to the use of complex potentials, which play a pivotal role in fracture mechanics. By further simplifying the general elasticity equations into one-dimensional models, students build upon the theory covered in classical courses on the elasticity of structural members (beams/bars), while extending the scope to focus on energy-based and variational principles, as well as methods for calculating stress and deformation. These methods are rooted in the principle of virtual displacements and virtual forces, as well as the variation of strain energy and complementary energy. The course culminates in the study of direct variational methods, which form the basis of the Finite Element Method, and their application to one-dimensional elasticity problems.
The study programmes with the given course
Programme N-MAI-P: Mathematical Engineering, Master's, elective
Type of course unit
Lecture
39 hours, optionally
Syllabus
- Kinetics – stress at a point.
- Kinematics – strain at a point.
- Laws of thermodynamics.
- Generalized Hooke’s law, strain energy density, thermoelastic constitutive equations.
- Boundary value problems in continuum mechanics, existence and uniqueness of solutions, equations for stress in structural members (tension, bending, torsion), and plane elasticity.
- Anisotropic plane elasticity – Lekhnitskii-Eshelby-Stroh (LES) formalism and its application in fracture mechanics.
- Isotropic plane elasticity – Muskhelishvili’s complex potentials and their application in fracture mechanics.
- Work and energy, strain energy and complementary strain energy, Hamilton’s principle.
- Method of virtual displacements, method of virtual forces, Castigliano’s first and second theorems, Betti’s and Maxwell’s reciprocal theorems.
- Direct variational methods – Ritz and Galerkin methods.
- Finite element method.
- Finite element method.
- Discussion and end of the semester.
Exercise
39 hours, compulsory
Syllabus
- Kinetics – stress at a point (Exercises 1–2).
- Kinematics – strain at a point (Exercise 3).
- Boundary-value problems in continuum mechanics; existence and uniqueness of solutions; equations for structural members under tension, bending, and torsion; plane elasticity (Exercises 4–5).
- Anisotropic plane elasticity – Lekhnitskii-Eshelby-Stroh (LES) formalism and its application in fracture mechanics (Exercises 6–7).
- Isotropic plane elasticity – Muskhelishvili’s complex potentials and their application in fracture mechanics (Exercise 8).
- Work and energy; strain energy and complementary strain energy; Hamilton’s principle (Exercise 9).
- Method of virtual displacements, method of virtual loads, Castigliano’s first and second theorems, Betti’s and Maxwell’s reciprocal theorems (Exercises 10–11).
- Direct variational methods – Ritz and Galerkin methods (Exercises 12–13).