FOUNDATION INHOMOGENEITY IDENTIFICATION BASED ON GENERALIZED RIGID MODAL ANALYSIS OF FREE BEAM ON FOUNDATION

摘要

The rigid modal of free beam on inhomogeneous foundation was calculated, and the variable regularity of modal frequency and modal shape with the inhomogeneous foundation was analyzed in this paper. Because of the inhomogeneity of Winkler foundation and bedding reaction coefficient, the frequencies and shapes of rigid modal varies. As the varying characteristics of rigid modal were studied, the foundation's varying trend and degree could be identified. In order to considering the affection of soil under and around the beam, double-parameter foundation model was introduced. Based on Hamilton principle and calculus of variation, the vibration equation of beam on double-parameter foundation was deduced and significance conclusions were drawn, such as, the foundation parameters and its inhomogeneity can be identified.