Node-based wave analysis method for the dynamic response and stiffness of long-span cable-stayed bridges

• Published in: Structures (Oxford) 2024-01, Vol.59, p.105722, Article 105722
• Main Authors: Ji, Jianyi, Huang, Shiping, Akbar, Yasir, Huang, Kunhong, Wang, Ronghui
• Format: Article
• Language: English
• Subjects: In situ measurements; Kelvin-Voigt damping; Long-span cable-stayed bridge; Wave analysis; Wave velocity
• ISSN: 2352-0124; 2352-0124
• DOI: 10.1016/j.istruc.2023.105722

For dynamic analysis of long-span cable-stayed bridges (LCB) with high flexibility and long force transmission paths, wave analysis method offers unique advantages over modal analysis. However, conducting wave analysis for the entire LCB poses challenges due to the modeling complexity and the substantial computational cost associated with solving numerous wave equations. Therefore, a simple analytical approach for wave analysis of LCB is proposed, which entails the discretization of the entire bridge into waveguides and the subsequent recombination of the regularized local wave propagation models. The feasibility and strategy of solving the global propagation function using local double coordinate systems and specific node-based local wave propagation models are demonstrated. Additionally, based on the geometric and mechanical configuration of nodes in the LCB, local wave scattering and propagation models corresponding to the four standardized nodes types are proposed. A unified Node-Based Wave Analysis (NWA) method for LCB is developed, considering the viscoelastic behavior of cable-stayed beams according to the Kelvin-Voigt model to enhance structural realism. The reasonable damping coefficient in bridge is determined by means of theory and dynamic in situ test of three bridges. Finally, an extended case study is conducted on a typical two-pylon cable-stayed bridge, focusing on the impact of moving loads and material properties on wave characteristics. The results demonstrate the reliability of the proposed NWA method in predicting wave energy distribution, highlighting the suitability of wave analysis for dynamic analysis of LCB. In comparison to undamped structures, it has been found that the presence of damping results in a pair of additional flexural waves with a new dispersion relation in cable-stayed bridges. Furthermore, the study reveals the stiffness enhancement mechanism associated with wave dispersion characteristics in cable-stayed bridges.