Efficient isogeometric formulation for vibration analysis of complex spatial beam structures

Efficient isogeometric curved beam element is formulated to investigate the free vibration behavior of spatial beam structures with arbitrary curvature and torsion. Beam structures are described by multi-patch non-uniform rational B-splines. Isogeometric formulation with Timoshenko beam theory is applied with global formulation. Compared with prior formulations that use local formulation within a single patch, the present global formulation of stiffness and mass matrices for multi patch structures is effective in dealing with complex structures. Numerical tests are carried out on a series of models including a conceptual framework of an automobile to show the effectiveness of the present method.