• Citer

Damage detection and passive damping in suspension bridges

par Meng, Fanhao
Président du jury Garone, Emanuele
Promoteur Kinnaert, Michel ;Yu, Jingjun
Co-Promoteur Preumont, André
Publication Non publié, 2019-07-03

Thèse de doctorat

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

This thesis investigates the structural health monitoring and damping of suspension bridges, focusing on the three core issues: modal identification, damage detection and passive damping.The first part (chapter 2) presents the models of a pedestrian bridge including numerical (FE) models and a laboratory mock-up. The second part (chapter 3) presents a study of system identification procedures for modal identification based on ambient vibration measurement. The proposed study contains the conventional methods and blind source separation (BSS) techniques, here the conventional methods are important references used to verify the effectiveness of the complexity pursuit (CP) algorithm and generalized eigen decomposition (GED) algorithm. Through comparing the identification accuracy, noise sensitivity and stability of each method, stochastic subspace identification (SSI) is a suitable modal identification method for suspension bridge.The third part (chapter 4) presents a successful, numerical and experimental implementa-tion of methods for damage detection in the hangers of suspension bridges. This study uses the modal flexibility (MF) method to detect the single and multiple damages with varied loca-tions and severity in the hangers. Alternatively, we investigated and validated experimentally the possibility to use active cables as a tool for exciting the structure to detect and locate damages in the hangers. Here, the sensitivity of the damage index can be enhanced by using several cables in multiple driving modes. The experimental results show that the hybrid drive with multiple active cables can improve significantly the damage detection capability and is able to detect single and multiples damages with small modal amplitudes.The fourth part (chapter 5) proposes a synthetic approach to design and implement two degrees of freedom tuned mass damper (2DOFs TMD), aimed at damping bending and tor-sional modes of bridge decks (it can also apply to other types of bridges like cable-stayed bridge). The proposed design has been simulated and implemented successfully on the sus-pension bridge mock-up. Comparing with the classical configuration of TMDs, the two 2DOFs TMDs not only achieve 8.8 dB to 13.8 dB amplitude reduction, but also reduce the weight penalty of TMD.