Indirect assessment of tension force in cables equipped with TMDs

Abstract

Abstract In this paper, an indirect method to obtain the actual tension force in stay cables is presented. It is based on a combined experimental and numerical approach, where the experimental measurement of the first natural frequency of the cable is combined with a FE model of the cable to finally obtain an estimate of the actual tension force. The method is suitable to be applied to cables eventually equipped with tuned mass dampers. It is here presented referred to an application case, the stays of the Hovenring Bridge. Being those cables endowed with two tuned mass dampers, the well-established indirect method based on the string theory cannot be applied to the present case. Therefore a new approach is proposed: it makes advantage of a FE model of the cable, made by equivalent tensioned beam elements and includes the effects of the dampers through equivalent mass-spring-damper systems. A complete description of the method is presented along with its validation through a comparison with a direct measurement of the tension force in 4 cables.