Bearing capacity calculation of reinforced concrete corbels under the shear action

The necessity of creating a general methodology for concrete and reinforced concrete elements strength calculation under the shear is established. Three failure cases of reinforced concrete corbels under the shear are considered. The solutions of problems of corbels strength with failure along the whole section, close to the normal, in the compressed zone under an inclined crack and within the compressed inclined strip are given. A variational method in the plasticity theory, the virtual velocities principle and the characteristic lines method are used for concrete and reinforced concrete elements calculations. In the ultimate state, concrete is considered as a rigid-plastic body. The shear is realized in case when the plastic deformation is localized in the compressed zone. The calculating ultimate load results for different failure cases are given. Such a design scheme is implemented, in which the console strength is minimal. This corresponds to the minimum of power of plastic deformation in concrete compressed zone. Reinforced concrete corbels calculation engineering methods are offered. The elements obtaining effective constructive decisions direction based on the plasticity theory use is determined

Розробка методики оцінювання напружено-деформованого стану позацентрово розтягнутих трубобетонних елементів

We developed a procedure for the evaluation of the stressed-deformed state of pipe-concrete elements that are stretched off-center with an entire cross-section. The obtained functional dependences make it possible to establish the magnitudes of stresses and strains in the pipe-shell and the concrete of pipe-concrete elements that are stretched off-center depending on geometrical characteristics and physical-mechanical properties of the element materials.The procedure takes into account the elastic stage of work of the materials considering the volumetric-stressed state and an increase in the loading from zero to destruction. The advantage of the developed procedure is the proposed simplified method for solving the system of defining equations based on the hypothesis about a joint work of the components of pipe-concrete (steel shell and concrete core) at all stages of loading with an off-center stretching effort. This procedure is implemented by consistently solving separate equations. The developed procedure for the evaluation of the stressed-deformed state of stretched pipe-concrete elements takes into account the negative impact of a bending moment, which is an additional force factor under conditions of the off-center stretching. Analysis of the comparison results of experimental data with those theoretical, obtained by the given procedure, confirms the hypothesis about joint work of the steel shell and the concrete core up until the moment when a pipe-concrete element that is stretched off-center runs out of its bearing capacity.The proposed procedure for the evaluation of the stressed-deformed state makes it possible with a sufficient accuracy to determine the bearing capacity of pipe-concrete elements that are stretched off-center with different geometrical parameters and mechanical properties. Results of the study could be applied when designing the structures by determining the bearing capacity of pipe-concrete elements exposed to stretching.Разработана методика оценки напряженно-деформированного состояния внецентренно растянутых трубобетонных элементов сплошного поперечного сечения. Получены теоретические зависимости. Определены значения напряжений і деформаций в оболочке и бетонном ядре в зависимости от геометрических характеристик и физико-механических свойств материалов. Учитывается объемно-напряженное состояние бетонного ядраРозроблено методику оцінки напружено-деформованого стану позацентрово розтягнутих трубобетонних елементів суцільного поперечного перерізу. Отримано теоретичні залежності. Визначено значення напружень і деформацій в оболонці та бетонному ядрі залежно від геометричних характеристик і фізико-механічних властивостей матеріалів. Ураховується об’ємно-напружений стан бетонного осерд

Development of a Procedure for the Evaluation of the Stressed-deformed State of Pipe-concrete Elements That Are Stretched Off-center

We developed a procedure for the evaluation of the stressed-deformed state of pipe-concrete elements that are stretched off-center with an entire cross-section. The obtained functional dependences make it possible to establish the magnitudes of stresses and strains in the pipe-shell and the concrete of pipe-concrete elements that are stretched off-center depending on geometrical characteristics and physical-mechanical properties of the element materials.The procedure takes into account the elastic stage of work of the materials considering the volumetric-stressed state and an increase in the loading from zero to destruction. The advantage of the developed procedure is the proposed simplified method for solving the system of defining equations based on the hypothesis about a joint work of the components of pipe-concrete (steel shell and concrete core) at all stages of loading with an off-center stretching effort. This procedure is implemented by consistently solving separate equations. The developed procedure for the evaluation of the stressed-deformed state of stretched pipe-concrete elements takes into account the negative impact of a bending moment, which is an additional force factor under conditions of the off-center stretching. Analysis of the comparison results of experimental data with those theoretical, obtained by the given procedure, confirms the hypothesis about joint work of the steel shell and the concrete core up until the moment when a pipe-concrete element that is stretched off-center runs out of its bearing capacity.The proposed procedure for the evaluation of the stressed-deformed state makes it possible with a sufficient accuracy to determine the bearing capacity of pipe-concrete elements that are stretched off-center with different geometrical parameters and mechanical properties. Results of the study could be applied when designing the structures by determining the bearing capacity of pipe-concrete elements exposed to stretching