Negative stiffness enhanced tuned mass damper (NS-TMD) for seismic induced response mitigation of isolated bridges

• Published in: Engineering structures Vol. 325; p. 119416
• Main Authors: Jiang, Shaodong, Ma, Ruisheng, Bi, Kaiming, Du, Xiuli, Song, Jian
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.02.2025
• Subjects: Control performance; Earthquake ground motions; Isolated bridge; Multi-objective optimization; Negative stiffness enhanced tuned mass damper; Control performance; Isolated bridge; Multi-objective optimization; Negative stiffness enhanced tuned mass damper; Earthquake ground motions
• ISSN: 0141-0296
• DOI: 10.1016/j.engstruct.2024.119416

Seismic isolators have been extensively utilized in the field of structural vibration control due to their superior control effectiveness in reducing absolute acceleration responses. However, this effectiveness comes with a compromise on large isolation deformation, which may result in various issues, such as pounding and/or unseating damages of bridge decks. To address these issues, a negative stiffness enhanced tuned mass damper (NS-TMD) was proposed, aiming to minimize absolute acceleration while simultaneously limiting isolation deformation, and its control effectiveness has been demonstrated. However, the previous studies primarily focused on single-objective optimization without considering NS-TMD stroke, and the conventional negative stiffness (NS) devices, e.g., the pre-compressed helical springs with revolute joints, could not be well compatible with NS-TMD due to limited operating range. To this end, this study proposes a novel NS-TMD, which consists of a TMD with a curved-type mass block and an NS element based on a cam-roller-spring (CRS) mechanism. The working mechanism of the novel NS-TMD is first introduced, and its mechanical model is formulated. This novel system is then applied to a typical isolated bridge to illustrate its control effectiveness. Equilibrium equations and state space formulations of the system are derived. Subsequently, parametric analysis on NS-TMD is performed, followed by the proposal of a multi-objective optimization strategy to simultaneously minimize the relative displacement of the bridge deck and the stroke of NS-TMD. Finally, the control performance of NS-TMD is systematically evaluated. Numerical results show that the optimized NS-TMD not only reduces the deck displacement of the bridge system (with a maximum reduction ratio of 49.50 %) but also decreases its absolute acceleration. Furthermore, NS-TMD can achieve superior control performance in terms of the deck displacement, while limiting the stroke within a reasonable range. In summary, NS-TMD is a highly efficient alternative to conventional TMDs in terms of control effectiveness and feasibility. [Display omitted] •The novel NS-TMD integrates a curved-type mass block with a CRS-based NS element.•A performance-based multi-objective optimization strategy for NS-TMD is developed.•Optimized NS-TMD simultaneously reduces both deck displacement and acceleration.•NS-TMD achieves superior control performance while limiting stroke within reasonable ranges.•NS-TMD surpasses conventional TMDs in control effectiveness.