Study on high frequency vibration-induced fatigue failure of antenna beam in a metro bogie

Sun

Proceedings of the Institution of Mechanical Engineers, Part F:

et al. 2023

The equipment mounted on the bogie frame of railway vehicles is subjected to non-stationary vibrations from the bogie frame. Currently, the vibration load spectrum for fatigue analysis of equipment is expressed with the power spectral density, which is generally obtained with the power values of measured vibrations or stationary Gaussian vibrations collected at the specific operating conditions. However, this does not have the equivalent damage potential as the non-stationary vibrations. Thus, a generation method of the vibration load spectrum is proposed based on the fatigue damage spectrum (FDS) to obtain the equivalent damage potential as the one from the non-stationary vibrations in this paper. That is, the FDS of non-stationary vibration is calculated with the time domain method, and the vibration load spectrum is generated in the frequency domain with this FDS. Then the method is verified by the measured vibration and dynamic strain of equipment. Finally, the vibration load spectrum of equipment mounted on the bogie frame is generated with the measured vibrations in a maintenance cycle and the fatigue analysis is performed. The results show that the generated vibration load spectrum can validly contain the high power in non-stationary vibrations and express the distribution of power over frequency, which gives much better estimates of the fatigue damage of equipment than other load spectra. The generated vibration load spectrum is suitable for quantifying the actual non-stationary vibrations and can be used for the anti-fatigue design of equipment.

Section: Introductionmentioning

confidence: 99%

Generation of vibration load spectrum for fatigue analysis of equipment mounted on bogie frame of railway vehicle based on fatigue damage spectrum

Sun

Proceedings of the Institution of Mechanical Engineers, Part F:

et al. 2023

Structural Health Monitoring

“…The corresponding resonance frequency of 63 Hz is identical to the bending mode of the lifeguard. Wu et al 4 pointed out that the rail corrugation-induced impact with a passing frequency of 78 Hz is the main reason for the modal resonance of the antenna beam in the metro bogie. Wang et al 5 found that the 17th-order wheel OOR could motivate the 1st expansion modal of the coil spring in the locomotives.…”

Section: Introductionmentioning

confidence: 99%

Fatigue stress estimation of metro bogie frame through frequency response functions by using limited sensors

Sun

Lai

et al. 2023

In this paper, the fatigue state estimation of the metro bogie frame is discussed based on limited sensors through frequency domain methods. The middle-frequency and high-frequency vibration fatigue damage cases of one metro bogie frame is discussed. The main excitations come from the wheel/rail interactions including wheel out-of-roundness and rail irregularities. The most common modal vibration of the bogie frame, where the transom bending deformation is dominant, is taken as the research object to study the possibilities of fatigue failure monitoring on concerned points of the bogie frame transom focusing on specific transfer paths. To eliminate unnecessary input signals which are not closely related to the occurrence of large stress amplitudes, the coherence analysis of different loads including the transmission load, carbody load and wheel-rail impact load is conducted through various methods including the short-time Fourier transform spectrum analysis, the magnitude-squared coherence analysis and the partial directed coherence analysis. Then the power spectral densities (PSDs) of the measured accelerations and cross power spectral densities (CPSDs) are calculated to obtain the transfer functions, whose output is the Y-axis stress at the concerned point. The stress PSDs are obtained using the instantly measured input accelerations and the prepared transfer function. Then the spectral moments and the stress amplitudes distribution functions are calculated through the frequency domain method to overcome the computational burden. The stress reconstructions based on inverse fast Fourier transform are analyzed and the fatigue damage results show good consistency with the experimental ones.

Advances in Mechanical Engineering

“…The results showed that the suitable non-destructive testing (NDT) inspection intervals were highly dependent on the specific axle design and service scenarios, particularly with regard to the effects of braking. Wu et al 18 investigated on the high frequency vibration-induced fatigue failure of antenna beam through both field tests and numerical simulation, which proved to be caused by the short pitch irregularities of rail. Besides, as wheel flats may excite various vibration modes of wheelsets employed in high-speed trains, the axle-box vibration and wheelset axle stress caused by a wheel flat on flexibility wheelset of high-speed railway trains was studied.…”

Section: Introductionmentioning

confidence: 99%

Structure failure analysis on metro axle-box hanger due to modal resonance with rail corrugation

Huo,

Wu,

Wang

et al. 2023

During the long-term service of a metro vehicle, different kinds of fracture failure occur on the bogie, with the axle-box hanger being a representative one. To investigate the cause of the hanger structure failure, a study was conducted that combined field investigation with finite element analysis, focusing on the modal resonance behavior between the hanger and the rail corrugation. Based on the findings, a structural optimization of the hanger was proposed and an experimental verification was conducted. The results show that the main reason for the hanger fracture failure is that the resonance phenomenon that occurred in the hanger structural modal frequency when exposed to the rail corrugation, leading to the poor lateral vibration environment of the hanger and the fracture failure in the long-term service operation. The first-order structural modal frequency of the hanger is 432 Hz, which is very close to the wheel/rail excitation frequency of 435 Hz caused by the rail corrugation. The modal frequency of three newly designed hangers can prevent the frequency caused by the rail corrugation. Experimental verification of the new hangers showed a 55.49% lower maximum average acceleration of hanger lateral vibration compared to the original structure, confirming the effectiveness of the redesigned hangers.