System Identification Including the Load Environment

Abstract

A number of methods for the identification of the axle loads of vehicles using a bridge’s static and pseudo-dynamic responses have been developed, 12345. Identification of moving loads has been studied separately by the authors, 678. However existing methods to identify the system parameters or the moving loads do not consider the influence from the environment or the system itself, respectively. This paper attempts to include the external force system in the identification of system parameters of a simply supported beam. The dynamic response of a prestressed beam under moving load is studied based on modal superposition in a forward problem. An inverse problem to identify both the prestress force and the moving load is then formulated. It is further extended to include the flexural rigidity of the beam as variable in the identification. Results from the studies indicate that the identification of both the system parameters and the moving loads with normal modal testing technique is feasible even with noisy data.