Equivalent dynamic beam-rod models of aircraft wing structures

The equivalent continuum beam-rod model of an aircraft wing structure with composite laminated skins has been developed based on the concept of energy equivalence. The equivalent structural properties of the continuum beam-rod model are obtained by directly comparing the reduced stiffness and mass matrices for a typical segment of aircraft wing with those for a finite element of continuum beam-rod model. The finite element stiffness and mass matrices are condensed through the well known finite element formulation procedure to be used in calculating the reduced stiffness and mass matrices for the aircraft wing segment in terms of the continuum degrees of freedom introduced in this paper. The present method of continuum modelling may yield every equivalent structural property including all possible couplings between bending, torsional and transverse shear deformations. To evaluate the equivalent continuum beam-rod model developed herein, the free vibration and aeroelastic analyses for a box-beam type aircraft wing structure have been conducted by using the continuum beam-rod model, and the numerical results are compared with the results by using other different models of the aircraft wing structure.