method for predicting movement of steel-rebar concrete composite columns considering concrete confinement provided by rebars and steel sections

摘要

The method for predicting the behavior of a steel-reinforced concrete composite column in consideration of the restraint effect of concrete by steel-reinforced heterogeneous members according to the present invention is: input; Calculating, in the control calculation unit, the concrete strain in the upper section of the steel-reinforced concrete composite column based on the basic data input from the input unit; Calculating the concrete strain in the lower section of the steel-reinforced concrete composite column in the control calculation unit after the step of calculating the concrete strain in the upper section; After the step of calculating the concrete strain in the lower section, increasing the control calculating unit so that the upper section strain in an arbitrary layer is increased step by step from 0; After the step of increasing the upper cross-sectional strain in the arbitrary layer step by step, increasing the control calculating unit to increase the concrete strain in the lower section in the optional layer stepwise from 0; determining, by the control calculation unit, whether a value obtained by multiplying the strain at the top of the section by the strain at the bottom of the section in the arbitrary layer is greater than 0; calculating an axial external force by the control calculation unit when the value obtained by multiplying the strain at the top of the section by the strain at the bottom of the section in an arbitrary layer is 0 or minus (-) based on the determination result of the control calculation unit; and calculating, by a control calculating unit, a nominal moment of a nominal moment after the calculating of the external force in the axial direction, wherein the nominal moment is calculated by the following equation. M_nominal = M_R/centroid + M_steel/centroid - M_conc/centroid Here, M_nominal is the nominal moment, M_R/centroid is the central moment of the rebar, M_steel/centroid is the central moment of the steel frame, and M_conc/centroid is the central moment of the concrete. Accordingly, when designing a steel-reinforced concrete composite column, the plasticity, inelasticity and It is possible to provide a method for predicting the behavior of a steel-reinforced concrete composite column in consideration of the restraint effect of concrete by steel-reinforced heterogeneous members, which conveniently derives nonlinear behavior.