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During the lifetime of a structural system, many severe events such as earthquakes and strong winds may impact the system and result in potential damage. To mitigate the structural vibration and damage during these extreme events, control devices such as active and semi‐active devices have received considerable attention because of their attractive characteristics. Active control devices are adaptable to any change and semi‐active devices have the capability of offering the reliability of passive devices and the versatility and adaptability of active devices. In this research, a direct‐adaptive‐control method is used to control the behavior of an undamaged and a damaged structure using semi‐active and active devices. In the adaptive control method, the controlled system is forced to behave like the model system which exhibits the desired behavior. The model of the adaptive control method is defined in a way to optimize the response of the controlled structure. The controller developed using this method can deal with changes that occur in the characteristics of the structure because it can modify its parameters during the control process. A magnetorheological (MR) damper is used as the semi‐active device in this study, whereas a hydraulic actuator is utilized as the active device to control the behavior of the structure. The performance of a three‐story building from the SAC project for the third generation of the control benchmark problem is studied by performing time–history analyses. The structure is subjected to different earthquakes and controlled by the direct adaptive control method. In the analysis of the structure, some stiffness reduction is assumed as a result of potential damage in the first story of the building. Also, the direct adaptive control strategy is used to optimize the response of the undamaged structure and to mitigate the damage impact on the performance of the controlled structure in the presence of noise for output measurements. The results of adaptive control method are compared with those of other control strategies. It is shown that the performance of the three‐story building is improved using the adaptive control method. By assessing the results of different control approaches, it is found that the adaptive control method works more effectively than other methods and semi‐active devices can provide reliable results.

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The use of semi-active devices for natural hazard mitigation is particularly attractive as they do not destabilize the structure and have the ability of adapting to varying usage patterns and loading conditions. However, even in the presence of supplemental control devices, extreme earthquake, wind loads, and deterioration caused by corrosion or fatigue may result in structural damage. Adaptive control approaches are attractive methods to control the structural performance of the structure as it can deal with these changes. In this study, first, the behavior of a 3-story building is controlled by a direct adaptive control approach using active devices, and then, magnetorheological (MR) dampers are controlled by the direct adaptive method. This control approach is used to reduce the impact of damage in the 3-story building. In the analysis of the structure, some stiffness reduction is assumed as a result of potential damage in different stories of the building. The controlled damaged structure responses under different ground motions are presented and compared with the uncontrolled damaged structure behavior. The goal of the adaptive control method in this research is to force the damaged structure to behave like an undamaged structure which performs acceptably. The effectiveness of this method in controlling the MR dampers is then verified.

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