Adaptive Control to Mitigate Damage Impact on Structural Response

Abstract

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.

Active and Semi‐active Adaptive Control for Undamaged and Damaged Building Structures Under Seismic Load

“…It is shown that the damaged structure displacement and acceleration would be smaller than the undamaged structure response for some earthquakes. The last issue is the limitations of the MR damper in generating the required force, which one of them is the upper and lower limit on the force produced by the MR damper (Bitaraf et al, 2010). The second constraint is that the MR damper forces have to be dissipative.…”

“…In the simulation for SACM, the matrices A p , B p , and C p in are defined as where M P is the mass matrix, and K P and C dP are the stiffness and damping matrices for the plant (controlled structure). The controllability and observability of the system is checked using Gilbert method (Gilbert, 1963; Bitaraf et al, 2010). The maximum accepted velocity for the model in SACM is assumed to be zero.…”

“…The PID control parameters, k P , k I , and k D , are chosen as 1, 100, and 0, respectively. Because the accelerometers are more general and available sensors than the sensors measuring velocity, velocities are obtained by numerical integration of accelerations (Bitaraf et al, 2010). It should be noted that the measured data become smoother and have offset by passing through integrator.…”

“…Bitaraf et al (2010) studied the effectiveness of using SACM to mitigate the impact of damage in the performance of a three‐story building equipped with MR dampers. The objective of the research was to force the damaged structure to behave like the undamaged structure.…”

“…By using this model in the SACM, the response of the controlled structure is always reduced, and the model output is independent of the characteristic of the earthquake which is applied to the structure. Bitaraf et al (2010) studied the effectiveness of using SACM to mitigate the impact of damage in the performance of a three-story building equipped with MR dampers. The objective of the research was to force the damaged structure to behave like the undamaged structure.…”