Application of time-frequency method for research on influence of locomotive wheel slip on vibration

Abstract

Wheel-rail contact phenomena is problem considered in many scientific manuscripts. Mostly the research is focused on wear, friction and forces analysis. This paper presents research on rail vibration generated due to rail vehicle passage. The problem investigated was the influence of wheel slip phenomena on vibration of rail. The locomotive wheel slip can be caused due to braking, flat wheel or defect (wear) of rail surface. Therefore, results of presented investigations can be useful for many applications, including rail vehicle driving monitoring system, control system, especially due to braking distance or diagnostics of wheels of railway tracks. The research was taken place on experimental test track. For the complex analysis horizontal and vertical vibration were measured. The investigation requires regular train vehicle drive condition, where the wheels are rolling on the rail surface without wheel slip and second case for drive process including wheel rolling and wheel slip (friction rolling and sliding). The vibration signals are non-stationary thus its processing should be conducted simultaneously in the time and frequency domain, as time-frequency representation (TFR). For this purpose, Short Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) can be employed.

Time-frequency methods of non-stationary vibroacoustic diagnostic signals processing

“…The presented state of affairs also applies to the operation and diagnostics of elements of the rail transport system. In [5,8,19,33,37] it is presented, among others, the use of non-stationary vibroacoustics signals for the detection of flat places on wheels, the detection of a slip phenomenon, identification of damage to the gear transmission or analysis of vibrations surrounded by railways. Therefore, it determines the necessity to develop the methods of signal processing allowing for the correct interpretation of the non-stationary diagnostic vibroacoustic signal.…”

“…Przedstawiony stan rzeczy dotyczy także eksploatacji i diagnostyki elementów systemu transportu szynowego. W kilku publikacjach [5,8,19,33,37] przedstawiono między innymi wykorzystanie niestacjonarnych sygnałów wibroakustycznych do detekcji płaskich miejsc na kołach, wykrywania zjawiska poślizgu, identyfikowanie uszkodzeń przekładni zębatej i analizy drgań w otoczeniu dróg szynowych. Determinuje więc to konieczność opracowania metod przetwarzania sygnałów pozwalających poprawnie zinterpretować niestacjonarny diagnostyczny sygnał wibroakustyczny.…”

Design and simulation of structural durability of passenger car front in collision

“…Liu analyzes the frontal collision on the bus chassis [6]. Some authors have studied, calculated, and simulated the structural strength of the passenger car's front and energy absorption in the collision [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In this study, Design a force absorption system at the front of the vehicle to ensure a safe space and the driver is not compromised.…”

Researching the force absorption system for the front of the passenger car to secure the driver

“…This study only shows the safety when the unbalanced car horizontally fl ips but omits the direct collision [6]. Currently, many authors apply simulation methods to calculate the safety of passenger cars [7][8][9]. Some researchers have applied the optimization method to improve the head car to protect drivers [10][11][12][13].…”