实时子结构混合试验中的Chang方法研究

Study on Chang method in real-time substructure hybrid testing

在传统显式Chang方法的基础上考虑试验子结构的质量影响,在作动器的常加速度假定和不考虑时滞影响的前提下,对作动器的位移进行中心差分得到作动器的加速度显式表达;认为作动器的加速度即为试验子结构的加速度,通过纯惯性试验子结构的实时子结构试验仿真对算法稳定性进行分析,发现当试验子结构的质量小于等于数值子结构的质量时,该方法的稳定性良好;在线性动力试验子结构中分析了试验子结构的质量、刚度、阻尼对算法稳定性的影响,发现该方法的稳定性同条件下优于修正的中心差分法。最后进行了地震作用下的仿真分析,表明该方法具有良好的精度。

Based on the conventional explicit Chang Method with consideration of experiment substructure inertial influence, under the assumption of constant acceleration of actuator and neglecting time-delay, explicit expression of acceleration of actuator is obtained by using central difference through displacement of actuator. We assume the ac- celeration of actuator is equal to that of substructure, the stability of the algorithm analysis is carried out by pure in- ertia substructure test. The results demonstrate that the proposed method has greater stability, when the mass of ex- perimental substructure is less than or equal to the mass of numerical substructure. The effects of mass, stiffness and damping of experimental substructure on the algorithm stability are simulated for linear experimental substructure. The results show that the proposed method has greater stability than modified central difference method. The accura- cy of the proposed method is proved to be high from simulation analysis under earthquake.