Estimation of tension force in double hangers by a system identification approach

Abstract

This article suggests a new technique for the estimation of tension of a double hanger cable system that is often used in a suspension bridge. The considered hanger system consists of the two independent parallel hanger cables tied by a lateral clamp. Measuring natural frequencies of the system, the hanger tension is determined by a frequency-based system identification technique with the aid of a finite element analysis. The proposed technique is able to simultaneously identify the tension, flexural rigidity and axial rigidity of the target hanger cable system. Laboratory experiments show that estimation errors of the proposed approach are less than 3%. For a relatively long hanger system in the field, the estimated results are similar to those evaluated by the existing methods. However, a significant difference is observed in a short hanger cable system.