Basics of deformation measurements and stress analysis

Lectures

Goal

The main objective of the class is to introduce students to the concepts of experimental diagnostics of structures, in the context of elastic and plastic behavior of materials. This primarily involves modern experimental methods for deformation measuring. Emphasis is placed on the processing of extensometer and optical methods (digital image correlation method) using modern electronics and optics.

Outcome

The student has mastered the techniques of experimental diagnostics of structures. He is able to conduct stress and strain analysis for complex multi-component stresses and to apply it to the assessment of the load-bearing capacity of simple structures.

Theoretical teaching

Stress analysis. Principal stresses and principal planes. Deformation analysis. Problem solving strategies and practical determination of stress distribution. Energy principles. Theoretical assumptions of the displacement method. Basic assumptions of the finite element method. Development and importance of experimental methods in structural diagnostics. Brief overview of existing measurement methods. Extensometers. Electrical resistance strain gauges. Optical measurement methods. Electrical resistance strain gauges – basic concepts. Types of strain gauges. Selection of strain gauges and their characteristics. Effect of temperature – temperature compensation. Continuous measurement of the deformation field using digital image correlation method.

Practical teaching

Determination of principal stresses and their directions for a known stress state at a point. Determination of extreme values ​​of shear stress in an arbitrarily stressed body. Examples of solving structural problems using displacement method. Practical application of experimental methods of displacement and deformation measuring on models of simple structures in laboratory conditions.

Attendance requirement

Without listening requirements and restrictions.

Resources

Handouts from Faculty (Department of Strength of Constructions) website. Computers having Finite Element Method based software installed. System for non-contact displacement and deformation measurement based on Digital Image Correlation.

Assigned hours

Total assigned hours: 60

Active teaching (theoretical)

New material: 30
Elaboration and examples (recapitulation): 0

Active teaching (practical)

Auditory exercises: 20
Laboratory exercises: 0
Calculation tasks: 0
Seminar paper: 0
Project: 0
Consultations: 0
Discussion/workshop: 0
Research study work: 0

Knowledge test

Review and grading of calculation tasks: 0
Review and grading of lab reports: 0
Review and grading of seminar papers: 0
Review and grading of the project: 0
Test: 5
Test: 0
Final exam: 5

Knowledge test (100 points total)

Activity during lectures: 0
Test/test: 50
Laboratory practice: 0
Calculation tasks: 0
Seminar paper: 10
Project: 0
Final exam: 40
Requirement for taking the exam (required number of points): 10

Literature

Handouts from Faculty (Department of Strength of Constructions) website.; В. Брчић, Р. Чилић, Експерименталне методе у пројектовању конструкција, Грађевинска књига, Београд (1988)