Practical technique for identifying characteristic matrices of railway vehicle carbodies based on stationary excitation tests

(Examintaion with the use of a scale model)

Abstract

In order to improve the vibration characteristics of the railway vehicle carbodies, some sorts of analytical models, such as a simple beam, a box-type and a finite element models, have been proposed. These models are constructed based on the equations of motions for some assumed or approximated structures. In this study, another modeling technique, without such assumption or approximation, are applied in which the mass, damping, and stiffness matrices (characteristic matrices) of the objective structure are identified with use of the frequency response functions (FRF) obtained in the stationary excitation tests. Two types of estimation methods, “direct FRF” and “modal” methods are investigated in this paper. These methods are firstly evaluated by applying them to the 4-degree-of-freedom system. The modal method is then applied to the scale model of the railway vehicle carbody, and it is confirmed that the identified characteristic matrices properly represent the relation between the excitation force and response vibration.