부산대학교 도서관

In this study, effective tangential modulus of the steel axial member with hot-rolled I-shaped section was investigated and suggested considering parabolic residual stress distribution. When finite element analysis is performed using beam element, some methods such as plastic zone method, elastic-plastic hinge method and refined plastic hinge method can be used for considering material nonlinearity of steel members. In conventional elastic-plastic hinge method and refined plastic hinge method, the CRC tangential modulus of steel members which have residual stress was used in order to consider gradual yielding effect induced by axial forces. But, the CRC tangential modulus was derived based on Euler`s inelastic buckling equation. So, it is not rational when the CRC tangential modulus is adopted for considering gradual yielding effect of axial member because the equation is relative with bending behavior. It is needed that the rational tangential modulus equation for axial members which have residual stress. The new effective tangential modulus was derived for considering gradual yielding effect of axial members which have parabolic residual stress pattern. As well as the shape of the stress pattern, maximum and minimum stress value can be considered. By nonlinear analysis using ABAQUS V6.10, suggested equation of the tangential equation was validated.