Peak Ground Acceleration’s Impact On Semi-Active Fuzzy Control Using Adjustable Liquid Damper

Articles in Press

Document Type : Original Article

Authors

• Javad Hashemi ¹
• Hamed Enayati ²

¹ MSc of Civil Engineering, Dept. of Civil Engineering, University of Science and Technology of Mazandaran, Behshahr, Iran

² Assistant Professor, Dept. of Civil Engineering, University of Science and Technology of Mazandaran, Behshahr,

10.22067/jfcei.2025.92219.1344

Abstract

Numerous tall buildings located in seismic zones require efficient control systems to mitigate the intense dynamic responses induced by earthquakes. Variable baffles tuned liquid dampers have been proposed as a semi-active control approach to reduce these responses. Conventional passive or optimally linear control systems may not consistently deliver optimal performance across all seismic scenarios. Therefore, the development of adaptable systems, such as fuzzy control with self-adjusting capability, appears essential. This study compares the performance of fuzzy control with passive and linear quadratic regulator control methods applied to a single-degree-of-freedom structure equipped with a liquid damper under various seismic excitations (near-fault, far-field, and near-fault pulse). The examined earthquakes ranged from 0.1 to 0.9 of peak ground acceleration, and twelve performance indices were utilized for evaluation. The results demonstrate that the fuzzy control system performs particularly well during near-fault pulse earthquakes (e.g., Kocaeli earthquake), achieving approximately a 20% reduction in roof displacement. As earthquake intensity increases, the effectiveness of this control method improves, with significant reductions in structural vibrations observed. In far-field earthquakes, the fuzzy control consistently performed on par with or better than the other methods, with an average displacement reduction of 2 to 5% across certain indices. However, some near-fault earthquakes exhibited slight increases in displacement and spectral response, attributed to the nonlinear nature of seismic ground motions in these zones. Additionally, in certain cases, the adaptive fuzzy control system's errors led to performance inferior to that of the linear quadratic regulator control method.

Keywords

• Peak Ground Acceleration
• Fuzzy Logic Control
• Structural Dynamic Response
• Tuned Liquid Damper
• Semi-Active Control

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