FREE-VIBRATIONS OF SANDWICH BEAMS WITH A TRANSVERSELY FLEXIBLE CORE - A HIGH-ORDER APPROACH

The analysis presented embodies a general rigorous approach including high order effects owing to the non-linearity of the displacement fields of the core caused by its flexibility in the vertical direction. In the high order approach beam theory is used for the skins and a two-dimensional elasticity theory for the core, and it is applicable to any type of sandwich construction, including non-symmetrical ones, and to any type of boundary conditions, including cases in which the conditions at the upper skin differ from those at the lower one. The results are described in terms of displacements in the various skins, longitudinal and vertical, and shear stresses in the core. Typical cases of a simply supported beam are numerically studied.