The control of structures with semi-active MR dampers

This thesis applied a semi-active control scheme to 5-8 story steel building models by adding an MR damper to the first floor. It aims to reduce the structural vibrations caused by earthquakes and increase the structures seismic performance. The applied semi-active control method consists of two stages: force control and current control of the MR damper. To calculate the reference control forces produced by MR damper PID, sliding mode and energy-based controllers, selected from the literature, were used simultaneously, unlike the existing studies. The functioning of the algorithms has been tested under real-time experiments. The current signal fed to the MR damper against the reference force determined by the controllers was calculated using artificial neural networks. The passive control method is also considered by using the uncontrolled state of the MR damper. Numerical verification was also done to make the semi-active control method more practical. In addition, the optimum damper placement has been tried to determine numerically by changing the location of the MR damper in the building. According to the data obtained from the study, the vibration responses of the semi-actively controlled structural systems with the MR damper have decreased significantly. The algorithms used to generate the control forces performed well in reducing the interstory drift, acceleration and especially base shear forces of the structural systems. However it has been shown that the performance of the controller varies according to the frequency and height of the structural system, earthquake forces and the working principle of the applied controller. The reduction rate varies according to the frequency and height of the structural design, the earthquake excitations and the applied controller working principle.