摘要
对于自由度较多的超高层结构,传感器优化布置时应考虑多阶模态振型。由于存在空间耦合振动,根据振型质量参与系数难以准确选择出结构弱轴方向的高阶振型。基于等效刚度参数识别法,本文提出了一种将有限元模型沿弱轴方向先简化为等效串联多自由度体系,然后根据简化结构的物理参数来计算弱轴方向振型矩阵的方法,有效地解决了这一问题。以某超高层结构为例,根据计算得到的系统振型矩阵,首先由其转置的列主元QR分解得到传感器的初始布置方案,然后以模态置信度(MAC)矩阵的最大非对角元为目标函数,采用逐步累积算法逐步增加可降低此初始布置MAC非对角元的结构自由度,并考虑经济性因素,最终确定出了传感器的布置方案。
The problem of sensor placement for a super high-rise building is discussed. Since the number of degree-of-freedom （DOF） of structure is large, multi-modes should be selected to describe the dynamic behavior of a structural system with sufficient accuracy to allow its health state to be determined effectively. A fundamental problem in analysis is how to accurately select the high-order modes. For this, a novel method computing the mode shape matrix of weak axis by simplified series multidegree-of-freedom system is developed based on the equivalent rigidity parameter identification method. The initial sensor assignment is obtained by the QR-factorization of the transpose of structural mode shape matrix. Taking the maximum off-diagonal element of the modal assurance criterion （MAC） matrix as a target function, adds one more sensor each time until the maximum off-diagonal element of MAC reaches the threshold. Considering the economic factor, the final plan of sensor placement of the building is determined.
出处
《计算力学学报》
EI
CAS
CSCD
北大核心
2008年第4期417-423,共7页
Chinese Journal of Computational Mechanics
基金
高等学校学科创新引智计划资助项目(B08014)
教育部长江学者和创新团队发展计划(IRT0518)
国家自然科学基金(50708013)
教育部高等学校博士学科点专项科研基金(20070141036)
中国博士后科学基金面上资助项目(20070420113)
沈阳建筑大学结构工程省级重点实验室开放基金(JG200718)资助项目
关键词
优化布置
模态置信度
QR分解
多自由度体系
超高层结构
optimal sensor placement
modal assurance criterion
QR-factorization
series of multide- gree-of freedom
super high-rise building
