Active tuned mass damper (ATMD) is widely adopted as a reliable active device to protect tall buildings subjected to earthquake excitations from severe seismic damages. Soil-structure interaction (SSI) phenomena effects on the free vibration characteristics and the seismic responses of tall structures. This study presents the design of an adaptive sliding sector controller (ASSC) for the active control of tall buildings equipped with an ATMD system considering the SSI effects. The ASSC technique is designed based on the hyper-surface of the sliding mode which is surrounded by a sector and can consider the uncertainty of system parameters. To validate the efficiency of the ASSC technique, its design is first implemented for a 40-story building equipped with an ATMD system under an artificial earthquake excitation for different soil types. Then, the performance of the designed ASSC technique is evaluated in mitigating the seismic responses of the structure subjected to five real earthquake excitations considering the SSI effects. In addition, the efficiency of the designed ASSC strategy is compared against that of the two controller techniques including proportional-integral-derivative (PID) and linear-quadratic regulator (LQR). Comparative results demonstrate the efficiency of the ASSC strategy for the reduction of the structural responses under real earthquake excitations.

This study investigates an optimized design approach for a passive -adaptive pendulum -tuned mass damper (PTMD). The PTMD is used to mitigate structural vibrations in offshore wind turbines (OWTs) with flexible monopile foundations considering Pile -Soil Interaction (PSI). The model OWT is based on the 5 -MW design proposed by the National Renewable Energy Laboratory (NREL). The PSI incorporates a pile that is modeled as beam-column elements supported by nonlinear springs and accounts for lateral loads (p -y curves) and axial loads (t -z and Q -z curves) at nodal points. Wind and wave spectra estimation, as well as hydrodynamic and aerodynamic load analysis, are performed using a bespoke MATLAB (R) program operated in conjunction with an ANSYS (R) 3-D finite element global model. The resultant peak response at the OWT hub was evaluated through power spectral density (PSD) analysis. Optimal design choices for PTMD parameters are obtained via parametric analysis, which assesses the dynamic response in the along and across directions at the hub and stress at the tower base. A systematic representation considers the uncertainties stemming from the geometric and mechanical properties of the tower, environmental loads, and rotating blade dynamics. To address these uncertainties, a Monte Carlo simulation is employed to assess the structural risk via the PerformanceBased Wind Engineering (PBWE) framework. Consequently, the probabilistic evaluation of structural response, foundation stresses, and power production assists in the optimal design process of PTMDs that mitigate the global structural vibrations of OWTs.