针对大型复杂结构的整体监测常常面临测量信息不足等困难,提出只利用局部动态响应进行子结构损伤识别的约束子结构方法。约束子结构方法是通过子结构响应的卷积组合限制子结构边界的响应为零,来实现施加虚拟支座,从而将子结构分离出整体,然后利用构造的相应子结构内部响应,进行子结构损伤识别。该文利用先分段提取结构响应的子时间序列,再延时排列Toeplitz矩阵的方式,使基于不同响应的构造约束子结构的方程具有相同表达式,统一了约束子结构方法的基本思想。通过测量悬臂梁的局部动力响应,利用局部响应的时间序列实现了子结构的快速准确地分离和识别,验证了方法的实用性和有效性。
For huge complex structures,it is difficult to obtain enough information which is required necessarily in their global monitoring.Aiming at this problem,a Substructure Isolation Method(SIM) is proposed for local damage identification.An isolated substructure is a virtual and independent structure,which is separated from a global structure by adding virtual supports on the substructure boundary to zero the substructure boundary responses.Correspondingly the interior responses of the isolated substructure are constructed and used to identify the local substructure damage equivalently.In order to reveal the essence of the Substructure Isolation Method and unify its basic concept,the way of arranging sub-time series is improved according to the SIM method based on impulse response,that is,sub-time series are extracted section by section,and then are arrayed into a Toeplitz matrix.In this way,it not only unifies the expression of SIM based on local time series and that based on impulse response,but also integrates the basic concept of SIM.An experiment of a cantilever beam is used to validate the efficiency and the practical application of this method.Both the substructure isolation and damage identification are performed successfully using local measured responses.