考虑物理加载时滞的力修正迭代混合试验方法

Force correction iterative hybrid test method considering physical loading time delay

为了提高传统迭代混合试验的收敛效率,提出考虑物理加载时滞的力修正迭代混合试验方法。该方法将数值子结构与试验子结构两部分进行全时程数据交互,其中包括时程内计算与加载的内环控制和时程间外环的迭代收敛控制。在时程内环通过力修正策略对运动方程数值积分中的试验子结构反力进行修正,同时结合三阶多项式外插方法对物理加载位移命令进行时滞补偿。在时程外环结合不动点迭代算法,建立外环迭代收敛控制器,以减小相邻两轮次之间的位移响应误差。以三层框架黏滞阻尼器减震结构为例,通过数值模拟对力修正策略进行了验证,进一步分析了加载时滞大小对迭代收敛性的影响。结果表明:力修正策略能有效提高迭代收敛效率,同时试验子结构反力修正精度越高收敛效率越高;物理加载时滞对迭代收敛性影响显著,时滞补偿能有效提高迭代收敛性。

Here, to improve convergence efficiency of traditional iterative hybrid tests, a force correction iterative hybrid test method considering physical loading time delay was proposed. This method could use numerical substructure and test substructure for full time history data interaction including inner loop control of calculation and loading within time history and iterative convergence control of outer loop between time histories. In inner loop of time history, reaction force of test substructure in numerical integration of equation of motion was corrected with the force correction strategy, and time delay compensation was performed for physical loading displacement command by combining third-order polynomial extrapolation method. In outer loop of time history, combined with the fixed-point iterative algorithm, outer loop iterative convergence controller was established to reduce displacement response error between adjacent two rounds. Taking a three-story frame structure with viscous dampers as an example, the force correction strategy was verified with numerical simulation, and effects of loading time delay on iteration convergence were further analyzed. The results showed that the force correction strategy can effectively improve iterative convergence efficiency, the higher the correction accuracy of reaction force of test substructure, the higher the convergence efficiency;time delay of physical loading has a significant impact on iterative convergence, time delay compensation can effectively improve iterative convergence.