Spatial Stability of Thin-Walled Eccentric Compressive Members

In this paper, a general method, called the spline finite member element method, is developed for spatial buckling analysis of thin-walled eccentric compressive members with arbitrary cross sections, considering warping. A transformed B3-spline function is used to simulate the longitudinal warping displacement field along the cross section of a thin-walled member. The method differs from Vlasov's classical theory of spatial buckling in that it takes into account the effects of shearing strains of the middle surface of walls on the buckling, which reflect the shear lag phenomenon. Compared with the results from the COSMOS/M finite element analysis program and another analysis method, the numerical results obtained in the paper demonstrate the versatility, accuracy, and efficiency of the proposed method. The fast convergence shown in numerical examples demonstrates the reliability of the results.