Optimal PD/PID control of smart base isolated buildings equipped with piezoelectric friction dampers

Long-period pulses in near-field earthquakes lead to large displacements in the base of isolated structures.To dissipate energy in isolated structures using semi-active control,piezoelectric friction dampers（PFD） can be employed.The performance of a PFD is highly dependent on the strategy applied to adjust its contact force.In this paper,the seismic control of a benchmark isolated building equipped with PFD using PD/PID controllers is developed.Using genetic algorithms,these controllers are optimized to create a balance between the performance and robustness of the closed-loop structural system.One advantage of this technique is that the controller forces can easily be estimated.In addition,the structure is equipped with only a single sensor at the base floor to measure the base displacement.Considering seven pairs of earthquakes and nine performance indices,the performance of the closed-loop system is evaluated.Then,the results are compared with those given by two well-known methods：the maximum possive operation of piezoelectric friction dampers and LQG controllers.The simulation results show that the proposed controllers perform better than the others in terms of simultaneous reduction of floor acceleration and maximum displacement of the isolator.Moreover,they are able to reduce the displacement of the isolator systems for different earthquakes without losing the advantages of isolation.

A hybrid LQR-PID control design for seismic control of buildings equipped with ATMD

This paper presents an efficient hybrid control approach through combining the idea of proportional- integral-derivative （PID） controller and linear quadratic regulator （LQR） control algorithm. The proposed LQR-PID controller, while having the advantage of the classical PID controller, is easy to implement in seismic-excited structures. Using an optimization procedure based on a cuckoo search （CS） algorithm, the LQR-PID controller is designed for a seismic- excited structure equipped with an active tuned mass damper （ATMD）. Considering four earthquakes, the performance of the proposed LQR-PID controller is evaluated. Then, the results are compared with those given by a LQR controller. The simulation results indicate that the LQR-PID performs better than the LQR controller in reduction of seismic responses of the structure in the terms of displacement and acceleration of stories of the structure.

Ranking of design scenarios of TMD for seismically excited structures using TOPSIS

In this paper,desigh scenarios of a tuned mass damper(TMD)for seismically excited structures are ranked.Accordingly,10 design scenarios in two cases,namely unconstrained and constrained for the maximum TMD,are considered in this study.A free search of the TMD parameters is performed using a particle swarm optimization(PSO)algorithm for optimum tuning of TMD parameters.Furthermore,nine criteria are adopted with respect to functional,operational,and economic views.A technique for order performance by similarity to ideal solution(TOPSIS)is utilized for ranking the adopted design scenarios of TMD.Numerical studies are conducted on a 10-story building equipped with TMD.Simulation results indicate that the minimization of the maximum story displacement is the optimum design scenario of TMD for the seismic-excited structure in the unconstrained case for the maximum TMD stroke.Furthermore,H2 of the displacement vector of the structure exhibited optimum ranking among the adopted design scenarios in the constrained case for the maximum TMD stroke.The findings of this study can be useful and important in the optimum design of TMD parameters with respect to functional,operational,and economic perspectives.