Petrenko D. The stress-strain state of flexible steel columns

The dissertation is devoted to experimental-theoretical research of short and flexible steel-concrete columns at static short-time loading with given eccentricities. The conducted review of literary sources suggests that steel structures are competitive compared to conventional reinforced concrete. The design of a deep sensor (one directional and three-dimensional socket) was developed and the nature of deformation development inside the concrete core and on the surface of the steel strips of steel concrete columns at different load stages was determined experimentally. Thanks to the methods of mathematical statistics, a mathematical model is proposed based on regression analysis to determine the bearing capacity of steel concrete columns. The paper presents an improved finite-element model in PC "Lira" which takes into account physical, geometric and constructive nonlinearities, evaluated stress-strain and boundary states. The satisfactory coincidence of experimental results and calculations performed on the proposed mathematical model obtained with the help of ITU in the software complex "Lira" is obtained, which allows us to conclude that the mathematical model corresponds to the investigated process of destruction of the column. The results of the dissertation work are introduced into the practice of designing and building, as well as in the educational process.