Inelastic Lateral Torsional Buckling of Beams

A numerical procedure is presented for predicting elastic and inelastic beam buckling loads. The procedure uses a finite difference solution to the differential equations defining lateral torsional buckling. The reduction in beam stiffness in the inelastic range is estimated by using an approximate tangent modulus method. A computer program has been developed using the numerical procedure presented for general elastic and inelastic buckling solutions. Solutions from the program are compared against approximately 123 test buckling results. Inelastic program buckling solutions are compared with and without using the shear center adjustment method. The approximate tangent modulus method and the shear center adjustment method agreed favorably with the test results.