Updating Methods Of FE Dynamic Model

As a method of structure analysis, the finite element (FE) analysis technique obtains mature development and comprehensive application. But there is a lot of error between FE model and practical model. Consequently, model updating procedure which is used to correct FE models has been introduced and widely used in recent years. Based on the analysis of various model updating methods, this paper presents two new updating methods to overcome their disadvantages:Considering the shortcoming of the matrix updating methods which can't preserve the physical connectivity information and have low computationally efficient, a new updating method with singular value decomposition (SVD) model is presented on the basis of the theories of multi degree of freedom vibration and SVD. Compared with matrix updating, this method improves the computationally efficient and preserves the physical connectivity information.Aiming at the shortcoming of the frequency response function (FRF) updating methods which have low computationally efficient and multi measure dimensions, a new updating method of dynamic structures is presented based on the model condensation technique and FRF. In order to improve the computationally efficient, the ratio of damp-to-stiffness is imported. Combining with the FE model condensation technique, the request of the testing model dimensions is decreased.Finally, numerical simulation result of multi axes gear drive systems shows the validity and feasibility of the method.