关键词: 工作模态参数识别, 邻域保留投影, 低维嵌入, 最小二乘广义逆

Abstract: To solve the problem of the low accuracy of Laplacian Eigenmaps and Isomap algorithm in identifying weak nonlinear feature modals,a new method of operational modal parameter identification using neighborhood preserving projection algorithm was proposed.The local linear feature was used to find the low-dimensional embedding of structural displacement response data,which was corresponded to the modal coordinate response matrix.The modal natural frequencies of the structure were identified from the modal response matrix by single degree of freedom identification technology.The transformation matrix was estimated by the Moore-Penrose matrix inverse,and the transformation matrix corresponded to the modal shapes matrix.The proposed method could preserve the local linear characteristics of the data and identify the weak nonlinear modals.The identification results of three-dimensional cylindrical shells simulation dataset showed that the neighborhood preserving projection algorithm was more effective and had higher identification accuracy in identifying parameters of weak nonlinear feature modals than Laplacian Eigenmaps and Isomap.

Key words: operating modal parameters identification, neighborhood preserving projection, low dimensional embedding, moore-penrose matrix inverse