Course detail
Nonlinear mechanics
FAST-CD02Acad. year: 2013/2014
Index, tensor and matrix notations, vectors and tensors in mechanics, properties of tensors. Types and sources of nonlinear behavior of structures. More general definitions of stress and strain measures that are necessary for geometrical nonlinear analysis of structures. Fundamentals of material nonlinearity. Methods of numerical solution of nonlinear algebraic equations (Picard, Newton-Raphson, modified Newton-Rapshon, Riks). Post critical analysis of structures. Linear and nonlinear buckling. Application of the presented theory for the solution of particular nonlinear problems by a FEM program.
Language of instruction
Number of ECTS credits
Mode of study
Guarantor
Department
Learning outcomes of the course unit
Prerequisites
Co-requisites
Planned learning activities and teaching methods
Assesment methods and criteria linked to learning outcomes
Course curriculum
2. Fundamental laws i mechanics, kinds of ninlinearities by their sources, Eulerian and Lagrangian meshes, material and space coordinates, fundamentals in geometrical nonlinearity.
3. Srain measures (Green-Lagrange, Euler-Almansi, logarithmick, infinitesimál), their behaviour in large rotation and large deformation.
4. Stress measures (Cauchy, 1st Piola-Kirchhoff, 2nd Piola-Kirchhoff, corotational, Kirchoff) and transformatio between them.
5. Energeticaly konjugate stress and strain measures, two basic formulations in geometyric nonlinearity.
6. Influence of stress on stiffness, geometrical stiffness matrix.
7. Updated Lagrangian formulation, basic laws and tangential stiffness matrix.
8. Total Lagrangian formulation, basic laws and tangential stiffness matrix.
9. Objective stress rates, constitutive matrices, fundamentals of material nonlinearity.
10. Numerical methods of solution of the nonlinear algebraic equations, Picard method, Newton-Rapson method.
11. Modified Newton-Raphsonmethod, Riks method.
12. Linear and nonlinear stability.
13. Postcritical analysis.
Work placements
Aims
Specification of controlled education, way of implementation and compensation for absences
Recommended optional programme components
Prerequisites and corequisites
Basic literature
Servít, R., Drahoňovský, Z., Šejnoha, J. Kufner, V.: Teorie pružnosti a plasticity II. STNL/ALFA Praha, 1984. (CS)
Recommended reading
Desai, C. S, Siriwardane, H. J.: Constitutive Laws for Engineering Materials. Prentice - Hall, 1984.
Classification of course in study plans
Type of course unit
Lecture
Teacher / Lecturer
Syllabus
2. Fundamental laws i mechanics, kinds of ninlinearities by their sources, Eulerian and Lagrangian meshes, material and space coordinates, fundamentals in geometrical nonlinearity.
3. Srain measures (Green-Lagrange, Euler-Almansi, logarithmick, infinitesimál), their behaviour in large rotation and large deformation.
4. Stress measures (Cauchy, 1st Piola-Kirchhoff, 2nd Piola-Kirchhoff, corotational, Kirchoff) and transformatio between them.
5. Energeticaly konjugate stress and strain measures, two basic formulations in geometyric nonlinearity.
6. Influence of stress on stiffness, geometrical stiffness matrix.
7. Updated Lagrangian formulation, basic laws and tangential stiffness matrix.
8. Total Lagrangian formulation, basic laws and tangential stiffness matrix.
9. Objective stress rates, constitutive matrices, fundamentals of material nonlinearity.
10. Numerical methods of solution of the nonlinear algebraic equations, Picard method, Newton-Rapson method.
11. Modified Newton-Raphsonmethod, Riks method.
12. Linear and nonlinear stability.
13. Postcritical analysis.
Exercise
Teacher / Lecturer
Syllabus
2. Demonstration of the problems with a big rotations.
3. Demonstration of the differences between the 2nd order theory and the large deformations theory.
4. Exdamples on bending of beams with a big rotations of the order of radians.
5. Examples on calculations of cables.
6. Examples on calculations of membranes.
7. Examples on calculations of mechanismes.
8. Examples on calculations of stabilioty of beams.
9. Examples on calculations of stability of shells.
10. Comparison of the Newton-Raphson, modified Newton-Raphson and Picard methods.
11. Examples on postcritical analysis of beams.
12. Examples on postcritical analysis of shells.
13. Demostration of the explicit method in nonlinear dynamics.