Method for identifying damage to stay cables based on local beam deflection

Abstract

In this study, for the problem of difficulty in identifying the damage of diagonal cable using the overall beam deflection, a method of identifying the cable based on the flexibility matrix of local beam segments is proposed. The range of influence of cable damage on the deflection of beams under self-weight is investigated and analysed using the finite element method , and the results show that the damage of cables mainly affects the deflection in their vicinity, while the change of deflection at other locations is minimal; with the change of the location of damaged cables, the influence of the range also changes accordingly. Building on this, the relationship between the difference in deflection of local beams and the change in cable force before and after the cable damage is deduced by combining with the principle of structural mechanics, and the damage index ∆F is proposed, and the validity of the method is confirmed by experiments. The experimental results indicate that the deflection of the local beam can be utilized to assess the change in cable force, allowing for the identification of the damaged cable's location, specifically where the change in cable force is negative. The method is highly resistant to interference. The method can quickly and accurately locate the damaged cable.