The effect of fuzzy controller on damage of steel structure considering structural uncertainties

In this study, the effect of active and semi-active fuzzy logic controllers (flc) on the damage imposed on steel structures, considering structural uncertainties, are investigated. two flcs are designed for controlling the actuators and controllable viscous dampers as active and semi-active devices, respectively. fragility curves are used to show the probability of damage imposed on uncontrolled and controlled structures. they are developed in consideration with three performance levels specified in fema 356, including immediate occupancy (io), life safety (ls), and collapse prevention (cp). considering deterministic and probabilistic parameters for the structure, fragility curves are generated separately to investigate the effect of structural uncertainties on the damage. to simulate the structure including the probabilistic parameters, latin hypercube sampling is employed. effectiveness of the controllers is illustrated and verified using the simulated response of a 3-story nonlinear benchmark building excited by several ground motions. to compare the performance of fuzzy controllers, fragility curves are also generated for the structure controlled by lqg and clipped-optimal controllers. results show that flcs can reduce the probability of damage significantly. moreover, it is observed that the uncertainty in mass and yield strength has the greatest effect on the maximum drift of structure.