动力子结构试验加速度振荡及其控制

Acceleration Oscillation and Its Control in Dynamic Real-time Substructure Testing

考虑试件质量的实时子结构试验中,因为试验系统采用数字控制器,输入到物理试验系统的采样离散信号包含高频分量,所以试件的加速度响应出现高频振荡。研究了高频振荡产生的原因和控制高频振荡的方法。首先对物理试验系统建立传递函数模型,分析了高频振荡产生的机理。然后采用前置滤波和后置滤波结合的复合滤波方法来控制高频振荡。对纯质量和动力试件分别进行了阶跃输入和地震波加载试验仿真,结果验证了这种方法的优越性。最后,采用中心差分法对纯质量试件进行实时子结构试验仿真,验证了复合滤波控制方法的有效性。

In the real-time substructure test, considering the specimen mass and digital test system controller, the discrete signals inputted to physical test system include high frequency components, which may cause high frequency oscillation in specimen acceleration response. The cause of highfrequency oscillation and a method for controlling the oscillation are presented in this paper. Firstly, the transfer function of a physical test system was developed to analyze the mechanism of the highfrequency oscillation. Then, a composite filter combining pre-filter and post-filter was adopted to control the high-frequency oscillation. Numerical simulation of pure mass and dynamic specimens was carried out with step signal input and seismic wave input, respectively. Results validate the effectiveness of this method. Time-history simulation of a real-time substructure test with pure mass specimen shows the validity of the composite filter controlling method.