Analiza efektywności wzmacniania stalowych belek cienkościennych typu sigma kompozytami CFRP
Authors: Szewczak Ilona 
Published: February 2025

In this dissertation an analysis of the reinforcement efficiency of sigma thin-walled cold-rolled steel
beams using CFRP tapes was performed. In addition, the process of preparing and conducting laboratory tests including steel thin-walled sigma beams with two different cross-section heights, and
the method of developing numerical models in the Abaqus program was presented. The results
of laboratory tests were compared with the results of numerical tests. Moreover, the scope of laboratory
tests was expanded through the analysis of the efficiency of strengthening sigma steel thin-walled
beams using steel tapes, and the numerical tests were enriched by the analysis of the effective length
of anchoring CFRP tapes.
The dissertation consists of nine chapters. The first chapter contains an introduction, which
presents basic information about cold-formed steel thin-walled elements, i.e. definition, scope of their
application and selected issues concerning analysis of such elements. In addition, basic information
on CFRP composite materials was discussed, highlighting the advantages and disadvantages of
using them to reinforce steel structures.
The second chapter provides an overview of the literature concerning the current state of
knowledge in the field of testing thin-walled steel elements and strengthening them using CFRP tapes.
The third chapter describes the genesis of the topic of the thesis, discussing the reasons for
which research related to the reinforcement of sigma thin-walled steel beams with CFRP tapes
were undertaken.
The fourth chapter contains an overview of the literature concerning modern and traditional
methods of measurement used in the laboratory tests. Particular attention was paid to methods for
measuring of initial geometrical imperfections of steel elements and the measurement methods
used in this work were described.
The fifth chapter presents the research program. The block charts show the subsequent
actions and methods related to scientific research (laboratory test and numerical analysis), which
the author planned in order to prove the theses stated in the dissertation.
Chapter six describes the first part of the laboratory tests, which consists of material coupon
tests and full scale pilot tests. The method of preparing samples for tests, the scope of tests and
the obtained results were described.
Chapter seven contains a description of the second part of the full scale laboratory tests,
consisting of three stages. It describes the scope of research, method of sample preparation, model
of the test stand, as well as the results of research.
In the chapter eight, numerical models referring to the tested beams are characterized. In addition, the results of numerical simulations were presented and the results of experimental tests and
numerical analyses were compared.
Chapter nine summarizes the publication. It presents the conclusions resulting from laboratory
and numerical analyses, and discusses the directions of further research. At the end there is a list
of literature references cited in the paper.