利用压电主动构件进行自适应桁架结构的系统识别

SYSTEM IDENTIFICATION OF ADAPTIVE TRUSS STRUCTURES USING PIEZOELECTRIC ACTIVE MEMBERS

自适应衍架结构是用主动构件取代原桁架结构的某些重要构件而形成的一种新型结构，以实现其动态特性自适应于外界环境变化的能力。自适应桁架结构的系统建模，对于分析研究其动态特性非常必要。本文提出一种利用自适应桁架结构的主动构件作为激励源来进行动态测试的方法，从理论和实验上研究了其可行性和正确性，并指出该方法和传统模态参数识别方法的不同之处。文中还讨论了动态测试中主动构件的配置问题。通过一压电自适应桁架结构试验模型的模态实验，验证了文中所述方法的正确性。

Adaptive truss structures are a new kind of structures with integrated active members,whose dynamic characteristies can be beneficially modified to meet mission requirements.Active members containing actuating and sensing units are the major components of adaptive truss structures.Modeling of adaptive truss structures is a key step to analyze the structural dynamic characteristics.A new experimental modal analysis approach,in which active members are used as excitatiDn sources for modal test,has been proposed in this paper.The excitation forces generated by the active members, which are different from the excitation forces exerted on structures in the conventional modal test,are internal forces for the truss structures.The relation between internal excitation forces and external forces is revealed such that the traditional identification method can be adopted to obtain modal parameters of adaptive structures.Placement problem of the active member in adaptive truss structures is also discussed in this work. Modal test and analysis are conducted with a planar adaptive truss structure by using piezoelectric active members in order to verify the feasibility and effectiveness of the proposed method.