Course code BūvZ2048

Credit points 6

# Basic Theory of Structures

Total Hours in Course162

Number of hours for lectures32

Number of hours for seminars and practical classes24

Number of hours for laboratory classes8

Independent study hours98

Date of course confirmation10.03.2021

Responsible UnitInstitute of Civil Engineering and Wood Processing

### Course developers

Būvniecības un kokapstrādes institūts

Dr. sc. ing.

lect.

Mg. sc. ing.

## Jānis Kreilis

Dr. sc. ing.

### Prior knowledge

Fizi2004, Physics I

Mate1022, Mathematics II

### Course abstract

In this course students will learn the basics about the behaviour of structures and structural elements under loading. The acquired knowledge and skills include: main concepts of statics and strength of materials, the axioms of statics, supports and support reactions, force equilibrium conditions, determining internal forces by the method of sections, stresses and strains in tension, compression and bending, mechanical properties of materials, Hooke’s law, theory of simple bending, cross section properties, stability of compressed bar, beam’s deflection calculation, kinematics of point masses and rigid bodies, main concepts of kinetics and dynamics.

### Learning outcomes and their assessment

Knowledge: To know the laws, axioms, the main concepts and methods of analysis of mechanics and strength of materials used in the design of building structures.
The knowledge is estimated during the semester and at the end of the semester by theory tests available in the university e-learning platform.
Skills: 1) Use of the equations of equilibrium to calculate the reactions at the supports of structures. 2) Determining internal forces in bars and beams by the method of sections. 3) Calculating normal and shear stresses in members subjected to pure tension/compression or flexure with or without axial forces. 4) Use of Hooke’s law to estimate the deformations of bars.
The skills are estimated during the semester by solving practical problems and in the final exam at the end of the semester.
Competences: Understanding the influence of different loading on structures and ability to evaluate the critical areas of simple trusses and beams subjected to loading. The competences are evaluated in the oral exam.

### Course Content(Calendar)

1. Lectures: Structure as load redistributing system. Application of the theories of mechanics of rigid bodies and elastically deformable bodies in structural analysis. Main categories of statics (strength, stability, stiffness). The axioms of statics. (2hr)
Practical work. (2hr)
2. Lectures: The moment of a force. Summation of moments of parallel and unparallel forces. Varignon’s theorem. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)
3. Lectures: Equilibrium conditions of bodies. External forces acting on building structures. Determination of the support reactions based on the equations of equilibrium. (2hr)
Practical work. (2hr)
4. Lectures: Types of building structures and modelling of their behaviour. Analysis of systems of bar members. Degrees of freedom of movement. Basic conditions for geometrical stability of systems. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)
5. Lectures: Statically determinate bar structures. Methods for determining axial forces. Trusses. Determination of axial forces in trusses by the method of joints. (2hr)
Practical work. (2hr)
6. Lectures: Determination of axial forces in trusses by the method of sections. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)
7. Lectures: Mechanics of elastically deformable bodies. Hooke’s law. Stresses. Tension, compression, shear, bending and torsion. Normal stresses and shear stresses. Strains. Modulus of elasticity, modulus of shear.
Practical work. (2hr)
8. Lectures: Cross-sectional properties of bars. Calculation of cross-sectional properties for sections composed of basic shapes. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)
9. Lectures: Comparison of mechanical properties for different materials. Determination of the properties by means of experimental testing. (2hr)
Practical work. (2hr)
10. Lectures: The method of section. The conditions of equilibrium of internal and external forces at a section. Definitions and sign conventions of the internal forces (axial force, shear force, bending moment, torsion). 2D and 3D loading. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)
11. Lectures: Determination and graphical representation of internal forces of beams (diagrams of internal forces). (2hr)
Practical work. (2hr)
12. Lectures: Behaviour of beams subjected to bending. Normal stresses in cross-section. Tangential stresses. Strength criteria. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)
13. Lectures: Stability analysis of bars under axial compression. Euler’s theory. (2hr)
Practical work. (2hr)
14. Lectures: The differential equation of the elastic line of a beam. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)
15. Lectures: Kinematics of point masses and rigid bodies. Dynamics of point masses. (2hr)
Practical work. (2hr)
16. Lectures: Motion of point masses depending on forces. Dynamic/impact loads. (2hr)
Practical work. (1hr)
Laboratory work. (1hr)

### Requirements for awarding credit points

The evaluation process of students will take place during the whole semester that will end with the final test and the examination. The following order in the evaluation process is compulsory:
1. First the tests and practical works (design problems) must be completed; lectures must be attended (80% or more); all the reports of the laboratory works must be prepared and successfully defended.
2. Then students are allowed to take the final test.
3. After the final test is passed, students are permitted for examination.
The course is passed when the examination is passed successfully.

### Description of the organization and tasks of students’ independent work

During the semester student must participate and complete the following independent work:
1) Practical work – different problems of mechanics and strength of materials available in the university e-learning platform should be solved. They are available from the computer room of the department only.
2) Theory tests – all the theory tests in the course’s e-learning platform must be completed without assistance. They are accessible from the computer room of the department only.
3) Laboratory work – student must independently prepare the reports for all the experimental testing performed in the department’s laboratory.

### Criteria for Evaluating Learning Outcomes

1) At least 80% of the lectures must be attended. For every missing 10% (the percentage is rounded up to whole tens) an independent will be assign.
2) In practical work all the compulsory problems must be solved and the evaluation 100% must be obtained.
3) During the semester all the compulsory theory tests must be completed and the evaluation 100% must be obtained.
4) All the laboratory works must be attended, the reports must be prepared and defended.
5) If all the aforelisted criteria are completed, student gets the access to the final theory test available in e-learning platform. At least 80% of the points must be obtained in the test.
6) If the final test is passed, student defends his knowledge, skills and competences in oral exam. Student is evaluated according to the university’s evaluation scale.

2) Kepe O., Vība J. Teorētiskā mehānika. Rīga, 1982. 577 lpp.
3) Ziemelis I., Kaķītis A., Dominieks L. Materiālu pretestība : mācību grāmata. Jelgava: LLU, 2008. 376 lpp.
4) Seward, Derek. Understanding structures: analysis, materials, design/ Derek Seward. - 4th ed.- Basingstoke: Palgrave Macmillan, c2009, 367 lpp.