Finite-element model sensitivity in the vibration of partially embedded beams

Beams partially embedded in a Winkler foundation can exhibit the phenomenon of modal clustering. In this paper, a conventional Þnite-element package is used in the comparison of the natural frequencies of such beams as calculated using a discretized Þnite-element model and as computed from a closed-form exact solution. The sensitivity of Þnite-element models of varying degrees of reÞnement in predicting the incidence of modal clustering is discussed. It is shown that, in crude models, the clustering of modes is predicted accurately but other modes, even the lowest ones, can be unacceptably distorted. In very crude models, the Þnite-element analysis may fail altogether in identifying the modal-clustering phenomenon. Copyright