Natural frequency evaluation of a lightweight GFRP composite bogie frame

A glass-fiber-reinforced plastic (GFRP) composite bogie frame was designed and manufactured in this study. The lightweight GFRP bogie frame was designed to not only sustain heavy static and dynamic loads but also have a suspension function. Therefore, its dynamic characteristics are an important factor. In this study, its natural frequency was evaluated by means of a modal test and the test results were validated using a finite element analysis. Given these experimentally obtained dynamic characteristics, the running performance of a railway vehicle equipped with the GFRP bogie frame was assessed. The first bending natural frequency of the composite bogie frame was 22.8 Hz, which corresponds to 27.7% of the steel frame. The vehicle dynamic analysis results showed that the derailment index, dynamic wheel unloading, wheel wear index, and ride comfort satisfied the design requirements.