Experimental Study on Improving Seismic Stability of Building Structure with MR Dampers

第一年，在20 kN型磁流变阻尼器样机初步试验研究的基础上，设计、制造了最大行程为± 100 mm的40 kN新型磁流变阻尼器，并进行了试验验证，结果表明，该新型磁流变阻尼器具有良好的稳定的荷载-位移关系，并且可以通过施加较小的电流进行调节。通过将该阻尼器安装在一个简单的单质量模型中，模拟基础隔震建筑系统，通过振动台试验对项目参与者原有的半主动控制算法进行了研究。该模型由一个2/3比例的钢框架组成，该框架位于角柱底部的单向滚柱轴承上。使用四个天然橡胶支座将系统的固有周期调整为约3.0秒。采用40 kN磁流变阻尼器代替常规被动阻尼器进行半主动控制。对每个项目参与者提出的五种不同的控制算法进行了测试。每个算法的目标，即，在不引起较大位移的情况下获得较小的加速度，被认为是非常成功的。同时也证实了大多数实验结果与分析结果具有良好的一致性。

In the first year, based on the information obtained in the preliminary experimental study on the proto type 20kN MR damper, a new 40kN damper with the maximum stroke of ±100mm was designed, manufactured, tested and confirmed to be the one with satisfactory stable load-deflection relations which can be adjusted by applying minor electric current. By installing this damper into a small simple one-mass model to represent a base-isolated building system, original semi-active control algorithms by project participants were investigated by means of shake table tests.In the second year, a larger scale shake table test was conducted. The model consists of a 2/3-scale steel frame rested on one-way roller bearings at the foot of the corner columns. Four natural rubber bearings were used to adjust the natural period of the system to be about 3.0 seconds. Instead of a normal passive damper, the 40kN MR damper is installed to perform semi-active control. Five different control algorithms proposed by each project participants were tested. The aim of each algorithm, i.e., to get less acceleration without causing greater displacement than the case of normal passive control, was found to be very successful. It was also confirmed that most experimental results and analytical ones showed good agreement.