Modeling and Identifying of Non-Proportional Damping of Structures

Damping of structures is an important factor in structural dynamic analysis. It is very difficult to describe the damping property of the structures precisely. The common method to get damping model is to identify the parameters of the mathematical damping model by using the test mode information. The proportional damping matrix is one of the most useful damping models used in the numerical calculation for structural vibration, but cannot well represent the real phenomenon caused by damping pro-perty in structures. The non-proportional damping model is developed and improved during the past decades. A method is developed to identify the non-proportional damping matrix of structures. The damping matrix is based on “Liang’s damping model” which can correctly simulate the real structural damping more. Based on the test mode information, the uncoupled modal damping and modal stiffness can be obtained by using the decoupling method in real subspace. Then the proportional and the non-proportional parts of the damping matrix can be identified from the uncoupled modal damping and modal stiffness. A numerical example proves the feasibility of the method.