考虑结构质量未知的非链式结构系统识别方法

Identification of non-chain structural systems with unknown structural masses

目前已发展了许多基于结构振动响应进行结构系统识别的方法,但这些方法大都假定结构质量已知.虽然有部分学者研究涉及到质量未知的结构系统识别,但提出的方法还需要观测结构全部响应,尤其大多数为链式结构识别,对非链式结构研究很少.本文针对这些不足,研究考虑结构质量未知的非链式结构系统的识别,提出基于扩展卡尔曼滤波(EKF)方法,仅需要观测梁结构部分加速度响应,可同时识别结构的位移速度响应状态与未知的结构质量、刚度、阻尼参数.进一步推广了外激励未知情况下的扩展卡尔曼滤波(EKF-UI)方法,融合观测的结构部分加速度与应变响应,同时识别结构的位移速度响应状态与未知的结构质量、刚度和阻尼参数.并分别采用简支梁在已知和未知外激励下结构系统的识别算例,验证提出的两种方法的有效性.

Many methods of structural-system identification based on structural vibration responses have been developed.However,in these methods,structural masses are generally assumed to be known.In some identification methods,although unknown structural masses are considered,observations of all structural responses are required,thus leading to limitations of these methods.Especially,when the identification focuses on chained structures,these limitations become increasingly severe.To tackle limitations mentioned above,we propose the identification of non-chain structural systems with unknown structural masses.Based on the partial acceleration response of the beam structure,extended Kalman filter(EKF)is used to simultaneously identify the structural displacement and velocity responses as well as unknown structural masses,stiffness and damping parameters.In addition,the study of the identification with unknown external excitations is further developed.Based on the fusion of the partial acceleration and strain response of the structure,EKF jointly with unknown input(EKF-UI)method developed by the authors is employed to simultaneously identify structural displacement-and-velocity responses and unknown structural mass,stiffness,and damping parameters.Finally,identification examples of simply-supported beams under known and unknown external excitations are used respectively to verify the effectiveness of these two proposed methods.