Flexible curved multi-functional sensors for air flow and vibration signal measurement of train bogie

Abstract The fluid–solid coupling effects with the aerodynamic noise and structural vibration signals play a great part in the measurement accuracy and fault diagnosis of train bogies. It is important to collect aerodynamic noise and structural vibration data for safety evaluation and online structural health monitoring (SHM) of the bogie, which brings new challenges to the integration and installation of the sensors in the limited space and complicated operating conditions of the train bogie. Flexible curved multi-functional sensors (FCMFSs) integrated with hot-film and structural vibration sensor units are designed for air flow and structural vibration measurement of the train bogie. Bogie vibration and wind tunnel test platforms with FCMFSs are built to measure the air flow velocity and vibration data on the bogie surface under different operating conditions. Piezoelectric polyvinylidene fluoride sensors are found to have significant output in wind tunnel and vibration experiments, and the hot-film sensor is only sensitive to the air flow signal. The effect of vibration signals on the hot-film sensor can be ignored, and it is helpful to improve the aerodynamic noise and structural vibration signal mesurement accuracy of the train bogie. The dynamic performance of the FCMFSs is verified at the Rail Transmit Base of East China Jiaotong University, and they are applied to SHM and rapid fault diagnosis of train bogies. The airflow distribution and vibration data are collected for safety assessment and fault diagnosis of the train bogie.