Direct identification and expansion of damping matrix for experimental–analytical hybrid modeling

The theory of direct experimental identification of damping matrix based on the dynamic stiffness matrix (DSM) method is further developed in this work. Based on the relationship between the DSMs of the smaller experimental model and larger analytical model, the mathematical relationship between the damping matrices of the two models is established. Examining the relationship, two methods are developed that can be used to expand the experimental damping matrix to the size of the analytical model. Validity of the expansion methods is demonstrated with numerical examples. The expanded damping matrix is intended to be combined with analytically formulated stiffness and mass matrices to build an experimental–analytical hybrid model. To find the frequency range, in which such a hybrid modeling is valid, a simple but effective method is developed.