Application of an improved experimental free-interface method to the component mode synthesis of a car-body structure

摘要

An improved experimental residual compensation technique in component mode synthesis, called IEFIM (improved experimental free-interface method), is developed. This technique is based on a free-interface method which has an advantage that the truncated mode set can be approximated from experimentally obtained frequency response functions (FRFs). The previous experimental CMS techniques have been derived on the MacNeal's formulation. However, the inertia contribution of high-frequency modes is ignored in this formulation. It is because the MacNeal's formulation uses the first-order approximation method compensating only the static residual terms. The proposed IEFIM is more accurate and more efficient than the MacNeal's formulation based ononly the static residual compensation. It is because both the static and dynamic residual terms are compensated from experimentally obtained FRFs. Furthermore, it is not necessary to use the FRFs measured only at the frequency point close of - Hz. In this paper, a free-interface method is discussed together with an experimental residual compensation technique and then the proposed method is demonstrated for a car-body structure model.