DYNAMIC FORCE IDENTIFICATION FOR BEAMLIKE STRUCTURES USING AN IMPROVED DYNAMIC STIFFNESS METHOD

In this study a procedure of dynamic force identification for beamlike structures is developed based on an improved dynamic stiffness method . In this procedure, the entire structure is first divided into substr uctures according to the excitation locations and the measured respons e sites. Each substructure is then represented by an equivalent elemen t. The resulting model only retains the degree of freedom (DOF) associ ated with the excitations and the measured responses and the DOF corre sponding to the boundaries of the structures. Because the technique pa rtly bypasses the processes of model parameters extraction, global mat rix inversion, and model reduction, it can eliminate many of the appro ximations and errors that may be introduced during these processes. Th e principle of the method is described in detail and its efficiency is demonstrated via numerical simulations of three different structures. The sensitivity of the estimated force to random noise is discussed a nd the limitation of the technique is pointed out. (C) 1996 John Wiley & Sons, Inc.