Course Details

# Elasticity and Plasticity

Academic Year 2022/23

BD005 course is part of 3 study plans

B-P-C-SI (N) Summer Semester 1st year

B-K-C-SI (N) Summer Semester 1st year

B-P-E-SI (N) Summer Semester 1st year

Basic equations of theory of elasticity, stress and strain analysis in point, two-dimensional problems – plane stress and plane strain, axisymmetric problems, duality solution of the problem, energy theorems, variational methods, theory of thick and thin plates, theory of shells, static solution of foundation structures, models of soil, basics of elastic-plastic analysis, physical equations for elastic-plastic material with hardening, analysis of elastic-plastic state structures, the plastic limit of load carrying capacity.

Course Guarantor

Institute

Objective

During the course the student will obtain knowledge about basic quantities and relations of theory of elasticity for solid, beam, plane and plate structures. He will be skilled in the basic laws of mechanics - the principle of the virtual work and the principle of minimum of potential energy - and variational methods - Ritz method and finite elements method. After finishing the course he will be able to apply these methods on mentioned types of structures, to derive finite elements and to use computational programs based on finite elements methods in practise.

Knowledge

By finishing the course, the student will know fundamental equation of elasticity describing the linear behavior of element. Student will be able to use virtual work principle for solving simple elasticity tasks. Student familiarize with Ritz method. Student is able to motel the structure as 2-D elasticity task (plane stress, deformation) and knows plate theory. Marginally have cognizance of shell theory. Student knows FEM principles and fundamentals of single type finite element derivation. Knowledge of Finite Element Method (FEM) is sufficient for understanding and usage programs based on FEM in practice.

Syllabus

1. A brief historical reference of the theory of elasticity. Fields in the theory of the continua and the definition of state variables.

2. Basic equations of elasticity. The derivation of geometric equations and physics equations. The properties of the strain and stress tensors. The equilibrium conditions and compatibility conditions.

3. Analysis of stress and strain in point. Plane stress and plane strain. Levy condition. Airy‘s stress function. Procedure for solving plane stress.

4. Axisymmetric problems - basic equations of plane problem in polar coordinates. Rheological models of material.

5. The deformation of non-force effects. Display of stress (Becker-Westergard, Mohr).

6. The potential energy of deformation and strain of work. Energy principles. The principle of virtual work and variational methods in continuum mechanics.

7. Theory of plates. Types of plates, boundary conditions. Special types of plates.

8. Analytical solution of plates in a rectangular coordinate system. Approximate solution of plates.

9. Introduction to the theory of shells. Membrane and bending state of stress. Internal forces with shells.

10. Static solution of foundations. Models of soil.

11. Basics elastic-plastic analysis. The physical equations for elastic-plastic material with hardening.

12. Analysis of elastic-plastic state. The limit state plastic bearing capacity of beam structures.

Prerequisites

Diagrams of internal forces on a beam, the meaning of the quantities: stress, strain and displacement, Hook’s law, equilibrium conditions for a beam, physical and geometrical equations for a beam. Stress states of beam and combinations thereof. Statically indeterminate beams systems and force and displacement methods of solution. The matrix notation of solutions.

Language of instruction

Czech

Credits

5 credits

Semester

summer

Forms and criteria of assessment

course-unit credit and examination

Specification of controlled instruction, the form of instruction, and the form of compensation of the absences

Extent and forms are specified by guarantor’s regulation updated for every academic year.

Offered to foreign students

Not to offer

Course on BUT site

Lecture

13 weeks, 2 hours/week, elective

Syllabus

1. A brief historical reference of the theory of elasticity. Fields in the theory of the continua and the definition of state variables.

2. Basic equations of elasticity. The derivation of geometric equations and physics equations. The properties of the strain and stress tensors. The equilibrium conditions and compatibility conditions.

3. Analysis of stress and strain in point. Plane stress and plane strain. Levy condition. Airy‘s stress function. Procedure for solving plane stress.

4. Axisymmetric problems - basic equations of plane problem in polar coordinates. Rheological models of material.

5. The deformation of non-force effects. Display of stress (Becker-Westergard, Mohr).

6. The potential energy of deformation and strain of work. Energy principles. The principle of virtual work and variational methods in continuum mechanics.

7. Theory of plates. Types of plates, boundary conditions. Special types of plates.

8. Analytical solution of plates in a rectangular coordinate system. Approximate solution of plates.

9. Introduction to the theory of shells. Membrane and bending state of stress. Internal forces with shells.

10. Static solution of foundations. Models of soil.

11. Basics elastic-plastic analysis. The physical equations for elastic-plastic material with hardening.

12. Analysis of elastic-plastic state. The limit state plastic bearing capacity of beam structures.

Exercise

13 weeks, 2 hours/week, compulsory

Syllabus

1. The calculation of stress and strain using equations of elasticity - the relationship between stress and strain.

2. The principal stresses (stress invariants), the calculation for different cases of stress.

3. Strength and plasticity criteria - calculation of equivalent stress by various theories.

4. The graphical representation of stress. The Mohr’s method.

5. Determining the work of external forces. Application of Lagrange and Castigliano's theorem. Calculation the strain energy.

6. Analytical solutions of wall – Airy stress function.

7. Principle of virtual work. Practical use of Castigliano‘s method.

8. Approximations of the line deflection of the beam by Ritz's method. Application of the Galerkin method for solving simple problems of elasticity

9. Classical solutions of plates - method of an infinite series.

10. Calculation graph of internal forces of a cylindrical shell.

11. Determination a limit plastic resistance of the beam and plate

12. Analysis of the formation of plastic hinges on a simple frame structure.