Kochkarov D. Nonlinear resistance of reinforced concrete elements and structures of force

Object – work and behavior of reinforced concrete elements and structures under load; aim – creation of computational models of stressed-deformed state of reinforced concrete elements that allow synthesizing the resistance of reinforcement and concrete resistance in the resistance of reinforced concrete, oriented to greatly simplify the calculation of structures of buildings and structures in accordance with the fundamental concepts and provisions of the science of material resistance; methods – mathematical and physical modeling of the strained-deformed state of loaded reinforced concrete elements in the aspect of nonlinear resistance of reinforced concrete to power influences on the basis of the data of mechanical test methods; experimental research of samples of concrete reinforced concrete elements in laboratory conditions using mechanical and electrotenzometric methods of measuring deformations of materials; general methods of theoretical and empirical research: analysis, synthesis, abstraction, induction, deduction; verification of individual theoretical positions by experimental and theoretical methods; introduction of research results into construction practice; novelty – a new methodology for assessing the stress-strain state of reinforced concrete elements in the conditions of their bending and compression at different stages of work is developed; for the first time, it was proposed to determine the deflections of reinforced concrete elements by curvature in the areas between cracks, without using the average section, as suggested by most researchers; for the first time a model has been developed for calculating the bearing capacity of reinforced concrete elements over inclined sections by the method of design resistance of reinforced concrete, taking into account the actual deformation diagrams of materials and accepted hypotheses; on the basis of the proposed deformation model, the method of calculating flexible non-centrifugally compressed elements and rod arch constructions is improved by non-iterative methods (without phenomenological approaches); for the first time synthesized strength and deformation physical and mechanical characteristics of reinforced concrete as a composite material were obtained, which made it possible to develop a general practical method for calculating the bearing capacity and stiffness of reinforced concrete elements; a modified method of applying the introduced design resistance of reinforced concrete has been developed, which reveals the broad possibilities for calculating reinforced concrete elements; results – a methodology has been developed for calculating reinforced concrete rod elements and the construction of rod systems within the framework of the proposed hypotheses; reasonably theoretically and experimentally confirmed the hypothesis of rigidity linearity; proposed dependencies to verify and refine experimental data; formulas are derived for the average stresses of adhesion of reinforcement to concrete; are derived confirmed resistance of reinforced concrete; a program for the calculation of reinforced concrete elements and core structures was developed, which verified the numerous experimental data of foreign and domestic researchers; the stages of the stressed-deformed state of reinforced concrete elements were added; have been developed methods for calculating the cross sections of reinforced concrete elements for the central extension, bending, eccentric compression, as well as methods for complex types of deformation; methods for the engineering calculation of rod systems of complex configuration have been developed; field – construction