DYNAMIC CONTINUUM MODELING OF BEAMLIKE SPACE STRUCTURES USING FINITE-ELEMENT MATRICES

A rational and straightforward method is introduced for developing equivalent continuum models of large beamlike periodic lattice structures based on energy equivalence. The extended Timoshenko beam model is chosen to account for coupling among extension, transverse shear, and bending deformations. The procedure for developing continuum models involves using existing finite-element matrices in calculating the strain and kinetic energies of a repeating cell. These results are then used to calculated the reduced equivalent continuum stiffness and mass matrices. The reduced finite-element stiffness and mass matrices are derived to provide a direct comparison with the reduced equivalent continuum stiffness and mass matrices. The equivalent continuum beam properties are obtained from the direct comparison. The numerical results of free vibration analysis show that the method developed in this paper gives very reliable dynamic characteristics compared to other methods. © 1990 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.