Vibrations of Space Structures

Abstract

The space structure is a circular cylindrical shell, constructed from a diamond mesh lattice skeleton of fibre composite material with a multi-layered outer skin of fibre composite material. This paper is concerned with the effects of the lattice periodicity on the vibrational modes of the structure and attention is directed to the simpler problem of the bending vibrations of a planar reticulated structure. The vibration frequencies of the plane skeleton are evaluated using the Bloch theory for periodic structures and these are compared with the frequencies of a continuum model which replaces the lattice structure by an equivalent plate. For the material constants employed here, it is shown that the continuum model provides an overestimate of the values which can amount to as much as 14%. Results are also presented for the skeleton with cladding, where the discrepancy between the two models is found to be much lower.