Course code BūvZ2039

Credit points 2

# Selected Topics in Strength of Materials

Total Hours in Course80

Number of hours for lectures16

Number of hours for laboratory classes16

Independent study hours48

Date of course confirmation18.12.2013

Responsible UnitDepartment of Structural Engineering

### Course developer Būvkonstrukciju katedra

## Bruno Ķirulis

Dr. sc. ing.

### Prior knowledge

BūvZ2048, Basic Theory of Structures

Fizi2007, Physic I

Mate1023, Mathematics I

### Course abstract

Material mechanics science, quantitative values of structural materials mechanical properties, structural element models. Deformations and stresses. Stress-strain analysis of beams under tension, compression, bending. Stability of bars. Time-dependance mechanical properties of materials and structures.

### Learning outcomes and their assessment

1. Student has knowledge about materials’ mechanical characteristics and ability to use appropriate dimensions in calculations, as well as to perform internal forces and strength analysis of bars and beams under tension, compression, bending. 1st Test, 1st Homework.

2. Student is able to choose an appropriate cross section form and to substantiate analytically the dimensions of rational cross section for beams correspondingly to internal forces acting. 2nd Test, 2nd Homework.

### Course Content(Calendar)

1. Material mechanics science, structural elements, their models.
2. Ideally elastic material, deformations un stresses, Hooke's law for tension, compression.
3. Mechanical properties of structural materials, characteristic force-deformation diagrams for different materials.
4. Experimental methods for determination of stresses and matherial strength.
5. Section stresses under planar stress condition.
6. Relationship between tangential stresses, maximal normal stresses and general axis angles.
7. Section method and internal forces (M, Q, N). Relation between internal forces and stresses.
8. In plane bending of beams. Differential relations between M, Q, q. Differential equation of beam axis displacement.
9. Deformations and stresses in beam sections under tension/compression/bending. Bending related normal- and tangential stresses.
10. Internal force diagrams and strength analysis of beam under tension/compression/bending.
11. Geometrical characteristics of beam cross section: area, area moments, moments of inertia.
12. Inertia moment transformation by coordinate axis translation and rotationships. Bending of complex cross section beams.
13. Shear deformations in torsion of beam section and stresses produced.
14. Stbility of bars under axial compression – general definitions.
15. Euler’s critical force formula. Support conditions and critical force.
16. Creep and stress relaxation, time-dependance of modulus of elasticity and strength of material.

### Requirements for awarding credit points

Credit test will be enrolled, if student know basic definitions of static, and he/she is able to discuss on results of calculations, to justify methods chosen. It is required positive assessment of tests.

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

1. test, 1. homework. Calculation of internal forces and stresses in beam under tension/compression/bending.
2. test, 2. homework. Calculation of beams rational cross section dimensions.

### Criteria for Evaluating Learning Outcomes

Student will have positive assessment of test, if at least 50% of calculation records are correct.
The home work will be assessed basing on two criteria: 1) fulfilment of equilibrium conditions between internal and external forces and correct force diagramms; 2) ability to participate in conversation on calculations and results.

1. Ziemelis I., Kaķītis A., Dominieks L. Materiālu pretestība. Jelgava: LLU, 2008. 376 lpp.
4. Sozen, Mete A. Understanding structures : an introduction to structural analysis / Mete A. Sozen, Toshikatsu Ichinose. - Boca Raton, FL : CRC Press, c2009