Course detail

# Strength of Materials I

Basic concepts and problems of strength analysis. Basic mechanical properties of material. Concepts of stress and strain. General theorems of linear elasticity. Definition and classification of bar and beam as the simplest model of a body. Bar under simple loading - tension / compression, torsion; bending of beams. Basic limit states of ductile and brittle materials under static loading. Safety conditions. Beams and bars under combined loading. Stability of compressed bars.

Language of instruction

Czech

Number of ECTS credits

7

Mode of study

Not applicable.

Learning outcomes of the course unit

Basic knowledge of stress and strain related to simple cases of loaded bars and beams and the idea of the boundaries of applicability of these classical approaches. Criteria of fundamental limit states and determination of safety and dimensions of designed bodies or machine parts.

Prerequisites

Basic knowledge of statics and mathematics. Statics - conditions of static equilibrium and equivalence, free-body diagrams, assessment of static determinacy, shear force and bending moment diagrams. Mathematics - vectors and matrices, differential and integral calculus, solutions to differential equations. Knowledge of the software Maple.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

The course is taught through lectures explaining the basic principles and theory of the discipline. Exercises are focused on practical topics presented in lectures.

Assesment methods and criteria linked to learning outcomes

The course-unit credit is granted under the condition of active participation in seminars and passing the seminar tests of basic knowledge (at least 10 ECTS points out of 20 must be gained). The points gained in seminar tests are included in the final course evaluation.
Final examination: Written part of the examination plays a decisive role, where the maximum of 80 ECTS points can be reached. Solution of several computational problems is demanded. The problems come from typical profile areas of given subject and supplied by a theoretical question, proof, etc. The lecturer will specify exact demands like the number and types problems during the semester preceding the examination.
Final evaluation of the course is obtained as the sum of ECTS points gained in seminars and at the examination. To pass the course, at least 50 points must be reached.

Course curriculum

Not applicable.

Work placements

Not applicable.

Aims

The objective of the course Strength Analysis I is to equip the students with methodology for determination of strain and stress in bodies and risk assessment of basic limit states. Practical experience with computations of the simplest bodies will be further supplemented with basic knowledge necessary for the strength design of real machine parts.

Specification of controlled education, way of implementation and compensation for absences

Attendance at practical training is obligatory. Head of seminars carry out continuous monitoring of student's presence, their activities and basic knowledge.

Recommended optional programme components

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

Gere, J.M., Timoshenko, S.P.: Mechanics of Materials, third SI edition, Chapman & Hall, London, Glasgow, New York, 1995
Pestel, E., Wittenburg, J.: Technische Mechanik, Band 2: Festigkeitslehre, B I, Wissenschaftsverlag, Mannheim, Leipzig, Wien, Zűrich, 1992
Hoschl, C.: Pružnost a pevnost ve strojírenství, SNTL, Praha, 1971

Not applicable.

eLearning

Classification of course in study plans

• Programme B-VTE-P Bachelor's, 1. year of study, summer semester, compulsory

• Programme B3A-P Bachelor's

branch B-MET , 2. year of study, summer semester, compulsory

• Programme B3S-P Bachelor's

branch B-STI , 2. year of study, summer semester, compulsory

• Programme B-PDS-P Bachelor's, 2. year of study, summer semester, compulsory
• Programme B-MAI-P Bachelor's, 2. year of study, summer semester, compulsory
• Programme B-FIN-P Bachelor's, 2. year of study, summer semester, compulsory-optional

#### Type of course unit

Lecture

52 hours, optionally

Teacher / Lecturer

Syllabus

1. Introduction to the course. Basic concepts - deformation, stress, strain, boundary conditions, and safety. Mechanical properties of materials and their computational models.
2. Behaviour of linear elastic body. Definition of the linear solids and structures. Basic theorems of linear solids and structures – theorem of reciprocity of work, deformation work of force and force system, Castigliano's theorem. Saint Venant’s principle.
3. Straight members in strength analysis - definition, classification. Geometric characteristics of the cross section. Planar moments of inertia and their transformations. Principal and central principal moments of inertia.
4. Simple tension and compression. Strain, stress, strain energy. Influence of imperfections on stress and strain. Safety of straight bar.
5. Statically indeterminate bars. Bar systems, combined systems of bars and general bodies. External and internal static indeterminacy.
6. Simple bending. Strain, stress, strain energy. Influence of imperfections on stress and strain. Shear stress caused by shear force. Safety of beams.
7. Statically indeterminate bars. Shear stress in thin-walled profiles, shear centre.
8. Weakly and strongly curved bars, frames.
9. Simple torsion. Stress, strain, strain energy. Influence of imperfections on stress and strain. Safety of bars in torsion. Statically indeterminate cases.
10. State of stress in a point of continuum, stress tensor, principal stresses. Representation of stress state in the Mohr’s plane. Special cases of stress state, plane stress.
11. Failure theories for ductile and brittle materials under static monotonic loading. Safety, equivalent stress. Behavior of material under cyclic loading, basic fatigue characteristics of material.
12. Bars and beams under combined loading. An overview of problems to be solved by analytical, numerical and experimental methods.
13. Stability of compressed bars. Influence of imperfections on critical force. Possible modes of failure of real bar under compression. Safety of compressed bars.

Guided consultation

26 hours, optionally

Teacher / Lecturer

Syllabus

Facultative tutorials will be dedicated to individual questions, discussions and possible application enhancement of the topics, presented in the time-schedule of lectures and seminars. Direct link to the time schedule of seminars is supposed.

Exercise

12 hours, compulsory

Teacher / Lecturer

Syllabus

1. Internal resultant forces and moments in a straight bar - differential approach.
2. Internal resultant forces and moments in a curved bar.
3. Tension/compression of bar, stress, strain and deformation. Statically determinate problems.
4. Tension/compression of bar systems, pin-jointed structures.
5. Bending. Stress, strain and deformation in statically indeterminate beams.
6. Torsion. Statically determinate and indeterminate tasks.

Computer-assisted exercise

14 hours, compulsory

Teacher / Lecturer

Syllabus

1. Internal resultant forces and moments in a frame in 2-D and 3-D.
2. Inertia moments of the cross section. Mohr’s diagram.
3. Tension/compression of bar, stress, strain and deformation. Statically indeterminate problems.
4. Bending. Stress, strain and deformation in statically determinate beams.
5. Curved bars and frames. Use of symmetry and anti-symmetry.