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.