Hajlított vasbeton tartók húzott övében fellépõ nemlineáris jelenségek figyelembevétele a görbületek és a feszültségek számításánál

Abstract

The paper presents the calculation of curvature and stresses of reinforced concrete cross-sections subjected to bending, to which the conventional assumptions on the cracked elastic state are only partly applied. Hooke's Law still holds true in the compression zone of the cross-section, but the strains in the steel reinforcement and in the tension zone of the concrete are larger than the yield strain. According to a proposed novel method, the bending moment and the balancing stresses, together the effective cross section need to be transformed in an appropriate way, so that curvature can be determined according to the common concepts related to the cracked-elastic state. However, due to the introduced auxiliary force, bending changes into eccentric loading. The application of this method is illustrated by examples involving steel reinforcement of three different material models and concrete of constant tensile strength. In the frame of a numerical example the paper introduces a little-known but efficient iterative procedure for the calculation of the location of the neutral axis, in case of cross-sections subjected to eccentric compression in cracked-elastic state.