Buckling of thin-walled compression members with shear lag using spline finite member element method

摘要

Based on the displacement variational principle a systematic semi-discrete method, called as spline finite member element method, is developed for buckling analysis of thin-walled compression members with arbitrary cross-sections in the present paper. The displacements at two ends of the member element are adopted as basic variables in the method. A transformed B_3-spline function presented in this paper is used to simulate the warping displacements along the cross-section of the thin-walled member. The analysis takes into account the effect of shearing strains of the middle surface of walls on the buckling, which reflect the shear lag phenomenon. Compared with the results from classical theory and the "COSMOS/M" finite element analysis program, the numerical results proposed in this paper demonstrate the versatility, accuracy and efficiency of the proposed method. The fast convergency shown in numerical examples predicts the reliability of the results.