Finite Element Model Updating of Suspension Bridge Based on Unstressed Length Identification

Abstract

<p>For suspension bridges, the cable structure usually tend to be slack under long-term loading. Therefore, the tension will be redistributed, thus leading to alter the mechanical characteristics and results in the failure of finite element model. In most cases, it is hard to be reflected intuitively by estimated tension. Therefore, the model updating method based on unstressed length identification was proposed. Based on the reference model, the cable force and elongation was estimated by influence matrix method. The stressed length could be measured precisely. Therefore, the unstressed length could be calculated. Because unstressed length is an inherent property, it will not be affected by external factors. A three-tower four-span self-anchored suspension bridge was taken to verify the method. The result showed that the sling relaxation could be detected by the unstressed length identification under the measure error less than</p><p>±8mm. Thus shows the superiority of the proposed method.</p>