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

第一年，根据20kN原型磁流变阻尼器的初步试验研究资料，设计、制造了一种最大行程为±100 mm的40kN新型阻尼器，并进行了试验，证实该阻尼器具有令人满意的稳定载荷-挠度关系，可通过施加小电流进行调节。通过将该阻尼器安装到一个简单的小型单质量建筑模型中来表示基础隔震建筑系统，通过振动台试验研究了项目参与者独创的半主动控制算法。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子轴承上。使用四个天然橡胶支座将系统的自振周期调整为约3.0秒。用40kN磁流变阻尼器代替普通的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。每种算法的目的，即获得较小的加速度而不引起较大的位移，比正常被动控制的情况被发现是非常成功的。也证实了大多数实验结果与分析结果吻合较好。

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.