Abstract
This paper presents an efficient finite element (FE) formulation for the 3D linear static analysis of thin-walled beams through displacement modes obtained from cross-sectional analysis. The formulation is suitable for the analysis of cross-sections made of homogeneous isotropic and/or laminated composite materials with arbitrary shapes. The FE formulation concerns all the warping and the distortional effects arise from the non-uniform torsion and the shear/bending, which leads to a higher order beam element. Unlike similar approaches, the method does not require the determination of rigid modes and the utilization of a full modal matrix. Although the cross-section displacement modes obtained from the solution of a quadratic eigenvalue problem are generally complex, the formulation itself does not have to deal with calculations involving complex numbers. The numerical results presented comparatively for several cases, demonstrate the accuracy and the computational efficiency of the presented beam element formulation compared to solid and shell formulations.