IDENTIFICATION OF PRESTRESS FORCE IN CONCRETE BEAMS BY FINITE ELEMENT MODEL UPDATING

This paper presents a numerical study of Finite element model updating to identify prestress force in a concrete beam. A finite element model for prestressed and reinforced concrete beam is developed. A newly developed optimization method, Clonal Selection Algorithm (CSA), is adopted for model updating calculations. Several objective functions, defined in terms of the static response, vibration frequencies of the beam, changes in the vibration frequencies, or the weighted combination of the static response and vibration frequencies, are used for finite element model updating. It is found that the changes in the vibration frequencies, among the four considered objective functions, give the best identification results of the prestress force in the beam. By smearing the vibration frequencies with different level of noises, the updating still successfully identified the prestress force. Numerical simulations demonstrate to the reliability of the method in identifying the prestress force in concrete beams.