Yasufumi Suzuki

Numerical Analysis of Three-Dimensional Flexural Vibration of Railway Vehicle Car Body

An analytical method to investigate the three-dimensional (3D) flexural vibration of railway vehicle car bodies is presented in this article. In the method, a car body is modeled as a box-type structure consisting of plates and beams. The condition to connect components is satisfied by introducing artificial springs at their joints. The detailed analytical procedure is described. Some numerical calculations are carried out employing a commuter vehicle, which has a stainless steel car body, as an example. The numerical results are compared with the measured data to evaluate the validity of the model. Although the target vehicle has complicated mode shapes, it is shown that the analytical model can express such 3D vibration mode shapes successfully. It is also demonstrated that a good agreement is observed between the calculation results by the above method and the measured data for both stationary excitation and running test.

Coupled Vibration of Passenger and Lightweight Car-Body in Consideration of Human-Body Biomechanics

Lightweight railway car body structure is a very important factor for the speeding up and energy saving of high-speed railway vehicles, such as magnetically levitated vehicles, and high-speed bullet train, Shinkansen. However, as lightening the car body decreases the bending rigidity of the car body, various elastic vibrations are liable to be induced in the car body, which results in deteriorating ride comfort for passengers. In this study, a special experimental set-up was made in order to investigate the coupled vibration of human body and flexible car body, the mass ratio of which is analogous to that of passengers and actual railway vehicles. After analyzing the behavior of human body affected by flexible car body vibration, computer simulation has been conducted by using a multi-degree-of-freedom flexible vehicle model of Shinkansen 700 series. The simulation analysis reveals that the resonant frequency of the first bending vibration mode depends on the passenger-seat dynamics, and the sensitiveness of the resonant peak is affected by the dynamic interaction, that is, coupled vibration between passengers and the car body.