Elastic buckling of orthotropic open section compression members with edge stiffeners

In this study, elastic buckling behavior of an orthotropic open section compression member with edge stiffener, which is one of the reinforcing methods for increasing local buckling strength of compression members, is investigated. In order to perform the local buckling analysis on the orthotropic structural shapes, the buckling analysis of orthotropic plates having various boundary conditions has to be done prior to performing the local buckling analysis since the structural shapes are composed of number of plate elements. Using these buckling analysis of the orthotropic plates, the closed-form characteristic equation for the local buckling of the orthotropic channel and I-shape compression members stiffened by the edge stiffener in their free edges is derived. Based on the results of the investigation, the minimum buckling coefficients with respect to the ratio between plate elements and the ratio between plate element to stiffener for the channel and I-shape compression members are shown graphically. This study shows the minimum buckling coefficient of orthotropic open section compression members with edge stiffeners is significantly increased in comparison with that of the columns with no edge stiffeners. Simple verification of the equation derived is performed by substituting the orthotropic material properties for isotropic ones and it is observed that the result is very close to that in published documents.