Numerical and experimental study on the interaction cable structure during the failure of a stay in a cable stayed bridge

摘要

Corrosion, abrasion and fretting fatigue may cause deterioration and, eventually, the failure of a post-tensioning tendon or a stay cable on a cable supported structure. In the present study, the stress acting during the rupture on the remaining portion of the stay which fails is derived, and the role of the rupture time on the response of the structure is discussed from a theoretical and a numerical point of view. In addition, the load-time curve during the rupture and the total time of the rupture of undamaged and damaged wires of seven-wire steel strands are investigated in an experimental program defined on the basis of the previous theoretical results. In the locally damaged specimens, a notch is machined into their outer wires. The specimens are tested under tension at three different strain rates in order to determine the influence of this parameter on the rupture time and on the load-time curve. The damaged specimens also allow us to determine the influence of a local reduction of the cross section on the stiffness and ultimate load of the specimen.