Abstract
It is very important to grasp the dynamic characteristics of machinery. Modal analysis is widely used as a basic technology for machine design. Various methods to identify the modal parameters of structures by the vibration test have been proposed. Recently, the frequency domain subspace method has been developed. Generally, it is easier to overview the dynamic properties of structures in frequency domain than in time domain. Therefore the frequency response functions (FRFs) are employed. In this paper, the modal parameters are identified by the frequency domain subspace algorithm. Then the residual terms derived from rigid body motions are considered. Additionally, it is important to determine the actual model order which is related to the identified state space model. Thus Akaike Information Criterion (AIC) is used to estimate the model order. The proposed procedure is applied to identify modal parameters of an aluminum circlar plate with a hole.
