In recent research, Jaehoon Bae, Xiameng Huang, and Ziwen Zhang have explored the advanced seismic resilience of steel moment-resisting frames equipped with hybrid viscoelastic friction dampers. This study, published in Scientific Reports, highlights the importance of improving building resilience against earthquakes, a critical issue given that buildings contribute significantly to global carbon emissions during seismic events. The researchers conducted extensive numerical simulations to assess how these dampers can enhance the performance of structures during strong earthquakes, ultimately aiming to minimize damage and ensure safety.
The core of this research lies in the use of VEFDs, which combine viscoelastic dampers with friction devices. Traditional velocity-dependent dampers can inadvertently increase axial forces in structural columns during seismic events, leading to potential failure due to the formation of plastic hinges. The innovative VEFDs mitigate this issue by controlling the peak force exerted on the columns, thus reducing the likelihood of weak-layer failures. By integrating both viscoelastic and friction elements, these dampers not only decrease story drift and peak accelerations but also effectively lower base shear forces, which are crucial for maintaining the structural integrity of buildings.
In their study, Bae and colleagues simulated the seismic responses of 10- and 20-story buildings fitted with VEFDs using 20 different seismic ground motion records. The results demonstrated that the hybrid dampers significantly improved the resilience of the structures. Specifically, they found that buildings equipped with VEFDs showed reduced story drift and plastic deformation, thereby enhancing the overall ductility and strength of the structures during seismic events. This is particularly important for high-rise buildings where the risk of structural failure increases with height.
The researchers also conducted nonlinear dynamic analyses to evaluate the performance of these buildings under various seismic conditions. Their findings revealed that the VEFDs effectively controlled both the absolute floor acceleration and velocity, which are critical factors in preventing nonstructural damage during earthquakes. The study underscored the potential of VEFDs as a viable solution for performance-based seismic design, offering a dual advantage of reducing structural damage while simultaneously minimizing the forces acting on the structure.
One significant aspect of the study was the assessment of collapse probabilities for MRFs equipped with VEFDs. The results indicated that the use of these dampers not only enhances the resilience of the buildings but also significantly lowers the risk of collapse during severe seismic events. This is a crucial consideration for urban areas prone to earthquakes, where the safety of occupants and the preservation of infrastructure are paramount.
The design of the VEFDs involved careful consideration of various parameters, including the ratio of the peak forces generated by the dampers. The researchers experimented with different configurations to optimize the performance of the dampers in both 10-story and 20-story buildings. This parametric study provided valuable insights into how varying the damper characteristics can influence the overall seismic performance of the structures.
Ultimately, the research conducted by Bae, Huang, and Zhang presents a promising advancement in the field of seismic engineering. The hybrid VEFDs represent a significant step toward developing more resilient buildings that can withstand the forces of nature while minimizing damage and ensuring safety. With the increasing frequency and intensity of earthquakes globally, innovations like these are essential for creating sustainable and safe urban environments.
This study not only contributes to the academic understanding of seismic resilience but also has practical implications for architects, engineers, and policymakers involved in the design and construction of earthquake-resistant structures. As the demand for resilient buildings continues to grow, the implementation of technologies like VEFDs could play a crucial role in shaping the future of urban infrastructure.
