Advances of Calculating Mode Shape Derivatives in Structural System Identification

摘要

Derivatives of vibration mode shapes (eigenvectors) with respect to design parameters are very important in the structural system identification, especially in finite element (FE) model updating based on modal test data. This paper reviews and compares different direct and modal methods for calculating lode shape derivatives with respect to design parameters. They are Nelson's method, Epsilon decomposition method, Lanezos-reduced method, classical modal method, modified modal method, iterative modal method and shifted-iterative modal method. All methods are implemented in a general-purpose finite-element program and applied to two computer simulation examples: FORK and 3D-FRAHE.