Dynamic Performance Study On Magnetorheological Damper

Magnetorheological (MR) damper is a typical semi-active control device, which combines the adaptability of active devices and reliability of passive devices. Due to its mechanical simplicity, high dynamic range, low power requirements, large force capacity and robustness, MR damper show its potential to be wildly applied in anti-vibration on civil engineering structures. This dissertation studied the dynamic performance, dynamic model and response time theoretically and experimentally. The main contents and results are as followed:Firstly, experiments were done on two kinds of MR dampers with different dimensions to evaluate the effects of dimension on the adjustable range of damping force, and the influence of frequency on damping force. Furthermore, the influence of inertia force at high frequencies on the damping force was also researched.Secondly, based on the characteristics of the two kinds of MR dampers, the improved models of the two dampers'damping force were built separately, which considered damping force lag. The results indicated that the models not only presented good precision, but also had the merits such as few parameters and clear physical concepts. The models can successfully predict the characteristic of the damping force performance.Lastly, the response time of MR damper was tested and analyzed. Experimental results showed that the response time was in the range from ten to several hundred milliseconds. The analysis illustrated that the response time of damper were greatly influenced by the response time of coil, therefore, it can be improved by optimizing the performance of current driver.