A METHOD TO DETERMINE THE BOUNDARY-CONDITIONS OF THE FINITE-ELEMENT MODEL OF A SLENDER BEAM USING MEASURED MODAL PARAMETERS

In this paper, a method used to determine the boundary conditions of t he Finite Element Model of a slender beam with measured structure moda l parameters is presented. On deriving the method, the finite element model theory for dynamic calculating is used. Combined with the modal parameters from experiment, an FEM-modal parameter equation to determi ne the boundary conditions is put forward. For solving the equation, t hree methods are given. The first is the accurate method. The second i s the full mode computation method by means of generalized inverse mat rix. The third is the interpolation method of frequency. A numerical s imulation with computer is given and the results of calculation fully verify the effectiveness of the method offered and also verify that th e accuracy of the method is satisfying. Finally, an applied example is given and the results of calculation fully verify the effectiveness o f the method offered.