Structural health monitoring of bogie system based on transfer function method

The bogie serves as a pivotal structural and functional unit within the rail vehicle system, and any failure in its performance can critically affect the safety and reliability of railway operations. This paper aims to develop a bogie structural health monitoring system based on the transfer function. In this study, the rigid-flexible coupling model of the bogie system will be established through the parameters and data of a real vehicle system. Propose a method for calculating the transfer function through the cross spectral density and auto spectral density. In this study, the system is constructed with the 3-axial acceleration data of the axle box and the stress of a cowcatcher. Then, calculate the transfer function of the 3-input single output system. And the system error is corrected through the sliding window method. Subsequently, the transfer function is used to predict the stress of the cowcatcher. Finally, based on the Dirlik frequency domain fatigue life estimation method, the damage and remaining life of the cowcatcher were calculated by using the measured stress and the predicted stress by transfer function. The results show that the stress results of the two methods have good consistency in both time and frequency domains, with a maximum error of only 6.5 %. It illustrates that the method can reproduce the stress state of the bogie system well. Based on this method, structural health monitoring of the bogie system can be realized.