A new complex inverse eigensensitivity method for structural damping model identification

Abstract

Damping plays an important role in the structural stability and vibration control. However, damping properties are the most difficult to model analytically but can only be revealed by vibration test. The work presented in this paper provides an effective method to identify a structural damping model by correlating the analytical mass and stiffness matrices which are developed by finite element methods and are assumed to contain modeling errors, with measured complex eigenvalues and eigenvectors of a test structure. The method employs both analytical and measured complex modal data to calculate the required eigensensitivity coefficients which are then used to identify the damping model of a structure based on complex inverse eigensensitivity formulation. The method is developed based on the practical assumption that the measured coordinates are incomplete and the identified damping matrix is physically meaningful and possesses the same physical connectivity as that of the stiffness matrix. Numerical examples are given to demonstrate the practical applicability of the proposed method and the results shown are very promising.