Flexural-Torsional Buckling of Curved Members

A method of analyzing the elastic flexural-torsional buckling of plane curved I-section members is developed. The solutions of the in plane bending equation are substituted into the out-of-plane buckling equations which become linearized. These buckling equations, which contain the bending and torsion differential equations and the boundary and warping equations, are solved numerically by the method of finite integrals, and the critical load is obtained iteratively. Very good agreement is obtained between the results and known solutions. The method can also be used to give more accurate solutions for the buckling of curved as well as initially straight members by using the in plane geometry of the loaded member just before flexural-torsional buckling occurs instead of the unloaded geometry.