Karpiuk V. Reinforced concrete girder structures' calculation models in the complex deflected mode of bearing areas

The subject of investigation are the single, continuous, prestressed, eccentrically stretched and compressed reinforced concrete beams and girder elements in sections ща which besides the transversal and longitudinal forces and bending moments torsional moments arise; the goal is to elaborate the calculation models of the pointed constructions in the complex bearing areas' deflected mode on the basis of the new data about their strength, crack resistance, deformability and destruction peculiarities; to work out the general engineering method of their durability calculation, to improve and develop the total solution for the rod ferroconcrete construction's nonlinear deformation model; the methods are theoretical, experimental and numerical investigation of strength, crack resistance, deformability and another efficiency parameters of the studied elements based on the developed methodology of the system of full-scale and numerical experiments' implementation with the application of mathematical theory of planning; mathematical and physical modelling of the reinforced concrete girder structures' deflected mode; in the issue the pressing scientific and technical problem on the development of the new and improvement of the existing reinforced concrete girder structures' calculation models in the complex deflected mode of bearing areas has been solved using real material state diagrams, phenomenological concrete and reinforcement durability criteria, the results of the systems experimental examinations; the novelty is for the first the systemic affect of the structural factors' influence and external action's causes both separately and in their interaction on the studied elements' crack resistance, deformability and strength has been comprehensively defined; mechanism and new patterns of the bearing areas' destruction in the complex deflected mode has been identified and for the first time their dependence on the respective proportions of the investigated factors has been set; a new general engineering method for calculation of the bearing areas' strength has been proposed, this method is based on the selection of the most probable destruction schemes depending on the correlation of the studied factors and alternate consideration of them, that allowed to improve the convergence of the calculated and experimental data up to 5...12%; the adopted in the general form nonlinear deformation model of rod reinforced concrete construction has received the further development; the proposed modelling options of the studied elements' complex deflected mode give the opportunity to reproduce numerically the results of the experiment by means of the modern computing systems and to make a reliable strength forecast, primarily; the implementation has been conducted at the construction, reconstruction and renovation of buildings and structures of Odessa city, while developing of the national design standard, in the educational process.