Calculation of turning rigidity of I-section reinforced concrete elements with normal cracks

Abstract

The article provides a methodology for calculating the torsion of an I-beam element using its approximation in the form of a cross-rod system. The cross-sectional I-section is divided into a finite number of longitudinal rods of rectangular section. These rods focus on their axial, flexural and torsional stiffness. Longitudinal rods are connected by transverse vertical and horizontal rods. The transverse rods imitate the local deformation of the longitudinal rods at their contact with each other. In contrast to the previously proposed methodology, in order to reduce the number of unknowns for creating the basic scheme of a statically indeterminate system, it is proposed that not all transverse rods be cut, but only one step in the longitudinal direction. The forces in the longitudinal rods determined from this calculation are applied to the rods of the next step. The pitch of the transverse rods may be arbitrary. A method for determining the stiffness parameters of the rods of an approximating system is shown. The advantages of the proposed methodology are shown, which can significantly reduce the number of equations unknown in the system, calculate elements for bending with torsion, and also take into account the change in stiffness as a result of nonlinear work of materials and crack formation.