STRESS-STRAIN STATE OF BENT REINFORCED CONCRETE ELEMENTS OF CONTINUOUS AND COMPOSITE CROSS-SECTION BASED ON A REFINED NONLINEAR CALCULATION METHOD

Abstract

A calculation apparatus is proposed that allows considering the issues of deformability of reinforced concrete elements of solid and composite (prefabricated-monolithic) sections from a single position. The approach uses an iterative approach to determine deformations based on a deformation model of a quasi-homogeneous solid body using a nonlinear concrete deformation diagram and a piecewise linear reinforcement deformation diagram, equations of equilibrium of external forces and internal forces. The approach is possible to determine the parameters of the stress-strain state not only of the bent, but also for non-centrally compressed elements. The work of stretched concrete before the formation of cracks is also described by a nonlinear dependence, after that - a rectangular plot. For the compressed part of the section - when deformations are achieved In the calculation method, the stiffness distribution along the length of the element has a parabolic appearance (not piecewise linear and not in the form of a polyline), which allows for additional deflection from the action of transverse force in short reinforced concrete elements and can be used as an external unit for a computer-aided design system. The comparison of the data of the physical experiment, the parameters obtained by the proposed method is carried out. The conclusion is made about the correlation coefficient of the author's physical experiment data and the calculation results according to the proposed methodology. The prospects for the development of the approach and possible areas of its use are shown.