Welded Metal Structures Resource Forecasting

Major: Oil and Gas Engineering and Technology
Code of subject: 6.185.00.O.068
Credits: 4.50
Department: Department of Oil and Gas Engineering and Welding
Lecturer: Dr. Tech. Science Pokhmurska Hanna Vasylivna
Semester: 6 семестр
Mode of study: денна
Learning outcomes: Analyze and evaluate the technical condition of elements of technological equipment of oil and gas facilities by means of technical diagnostics in industrial and laboratory conditions (RN 14) The ability to perform calculations when developing the structures of elements and nodes taking into account progressive technological processes (FRN1.1) Knowledge of basic methods of research and analysis of loads, displacements, stress-strain state in structural elements, methods of design and verification calculations of products (FRN1.5) The ability to realize the need for lifelong learning in order to deepen the acquired and acquire new professional knowledge (AaR2)
Required prior and related subjects: - Mathematical modeling of the stress-strain state of oil and gas reservoirs and pipelines - Modern pipeline materials and their weldability - Pumps and compressor stations
Summary of the subject: Chapter 1. Classical theory of material fatigue. The history of the formation of the classical theory of fatigue of materials, its structure and stages of development. Basic definitions and designations of cyclic loads Weller's theory, low-cycle fatigue, Coffin-Manson equation, the law of linear damage summation Micromechanisms of fatigue failure in the classical theory of fatigue Chapter 2. Mechanics of fatigue failure as a process of initiation and propagation of cracks. The main provisions and problems of the mechanics of fatigue failure of materials. Calculation models for determining the nucleation periods of fatigue microcracks Calculation models for determining the kinetics of fatigue microcrack growth Calculation models for determining the initiation period of a fatigue macrocrack Establishment based on the force approach of a system of equations for studying the kinetics of the propagation of fatigue macrocracks and determining the period of their critical growth An energetic approach for determining the period to critical growth of fatigue macrocracks. Energy balance equation in fatigue failure. Fatigue failure of welded joints An integral approach to determining the critical growth period of fatigue macrocracks in three-dimensional bodies. Chapter 3. Methods of determining the resource and residual resource of structural elements. Basic postulates for determining the service life of structural elements and welded joints Determination of the service life of welded joints made with seams with incomplete penetration: one-sided and two-sided butt-welded joints Application of fatigue fracture mechanics to determine the residual life of pipes. Residual resource of thick-walled pipes with technological surface cracks under impulse loading. Determination of the residual resource of the pipeline section near the pumping station, which is weakened by surface cracks.
Assessment methods and criteria: • protection of reports for laboratory works by an oral survey of theoretical material on the topic of the work and research methodology, current express control by means of a virtual educational environment (30 points) • final control (70 points, control measure, exam): written and oral form
Recommended books: 1. Skalskyi V.R., Bozhidarnik V.V., Dolinska I.Ya. Fundamentals of fracture mechanics for welders: training. manual - Lutsk, 2014. - 356 p. 2. Andreykiv O. Ye., Skalskyi V. R., Dolinska I. Ya. Delayed destruction of materials due to local creep. – Lviv: LNU named after Ivan Franko, 2017. – 400 p. 3. Andreykiv O.E., Shtayura S.T. Experimental mechanics of materials. Part 1. - Lviv: LNU, 2003. - 274 p. 4. Residual strength and durability of sections of oil and gas pipelines with defects: monograph [author. col.: Osadchuk V. A., Andreykiv O. E., Banakhevich Yu. V. and others]. - Lviv: Publishing House of Lviv Polytechnic, 2014. – 264 c. - ISBN 978-617-607-650-6.