主动桁架模态的试验研究

以一个78杆空间桁架为试验模型，研究线性主动结构构型的试验问题。对构型主动结构及特性分析的试验技术做了实践。采用耦合模态空间的二次型最优控制算法，利用压电堆作动器，构型了主动桁架。采用dAPACE半实物物理仿真操作平台，分别测试了被动桁架和主动桁架的模态振型和模态参数，并测试了主动桁架在随机激励作用下的传递函数。结果表明，主动结构由于引入了控制系统而使得结构的阻尼增大，同时由于在压电作动器附近的杆单元的模态受到抑制，所以主动桁架的模态与相应的被动桁架的模态存在着较大的差别。

Experimental Study on the Modes of Active Truss

By using a 78-bars space truss,the configuration and properties of a linear active structure are studied experimentally,and the experiment technique for constructing an active structure is practiced.The active truss is constructed by using piezoelectric stack actuators and adopting linear quadratic optimal control in coupling mode space.The modal shapes and modal parameters are,measured for active truss and passive truss respectively on active truss is measured when it is under a random excitation.It is shown that the damping of an active structure increases as a result of the control means introduced.Meanwhile,difference of the mode is much great between the passive truss and the active one because the mode of the bar is controlled nearby the piezoelectric actuators.