Flexible vibration analysis for car body of high-speed EMU

Shi, Huailong; Wu, Pingbo

doi:10.1007/s12206-015-1207-6

Cited by 55 publications

(29 citation statements)

References 9 publications

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“…Self-exited vibrations can be the result of the wheelset and bogie hunting motion due to the wheel-rail interaction forces. Based on the experimental results reported in the literature, 32 the forced vibrations are of higher frequency and are not related to the resonance of the car body. Track excitation, which is of the stochastic nature, does not have a constant frequency and produces the same effect on different trains.…”

Section: External Excitationmentioning

confidence: 97%

Effect of the tank car thickness on the nonlinear dynamics of railroad vehicles

Wang

Shi

Shabana

2016

Proceedings of the Institution of Mechanical Engineers, Part K:

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The expression of the centrifugal forces resulting from a flexible body negotiating a curve differs significantly from the expression of the centrifugal forces used in rigid body dynamics. In rigid body railroad vehicle dynamics, the balance speed does not depend on the body inertia; it depends on the vehicle speed, super elevation, track gauge, and gravity constant. This is not, however, the case when the structural flexibility is considered. In this paper, a general multibody system (MBS) approach that accounts for the nonlinear dynamic coupling between the wheel-rail contact forces and the tank car structural flexibility is used to examine the effect of increasing the tank car thickness on the nonlinear dynamics of railroad vehicles. The flexible tank cars are modelled in this investigation using the nonlinear finite element (FE) floating frame of reference (FFR) formulation. The tank car FE model is integrated with a computational railroad vehicle algorithm in which a three-dimensional elastic contact formulation is used to describe the rail-wheel interaction in order to allow for wheel-rail separations. A complete expression for the centrifugal and Coriolis forces is used with triangular shell finite elements to develop the tank car models with different thicknesses. The effect of the coupling between different modes of displacements is examined by comparing the results of the simulations of the flexible and rigid tank car models. A parametric study is performed in order to explain the effect of the thickness increase on the tank car natural frequencies. Furthermore, the effect of increasing the tank car thickness on the critical speed as well as on the nonlinear dynamics of the railroad vehicle during curve negotiation is examined. The FE/FFR formulation allows for accurately capturing the effect of the change of the tank car thickness on the centrifugal and Coriolis inertia forces that define the balance speed during curve negotiations. The analysis presented in this paper shows that there is a strong dynamic coupling between different modes of displacements of the tank car, the plate thickness, and the wheel-rail contact parameters. The effect of increasing the tank car thickness on the wheel wear is also examined in this paper.

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Section: External Excitationmentioning

confidence: 97%

Effect of the tank car thickness on the nonlinear dynamics of railroad vehicles

Wang

Shi

Shabana

2016

Proceedings of the Institution of Mechanical Engineers, Part K:

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“…Hence, free–free modes of the homogeneous Euler beam are acceptable. According to the elastic vibration theory, the partial differential equation of carbody vibration can be expressed as 16–18 where Z(x,t) is the vertical vibration displacement, which is the superposition of the rigid vibration and the elastic vibration of the carbody; x is the distance from the far-left position on the carbody; t is a time variable; E is the elastic modulus of the carbody; A is the sectional area of the carbody; μ is the internal damping coefficient; I is the inertial moments; ρ is the carbody density; Fs1 and Fs2 are the forces that are exerted on the flexible carbody by the secondary suspension of the first and second bogies, respectively; F d is the force that acts on the flexible carbody at the suspension point of the absorber; x i is the i th position of the secondary suspension; x 3 is the position of MREDVA; and δ(x-xi) and δ(x-x3) are Dirac functions …”

Section: Solution Of the Modelmentioning

confidence: 99%

Study on the vibration suppression of a flexible carbody for urban railway vehicles with a magnetorheological elastomer-based dynamic vibration absorber

Wen

Sun

Zhang

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part F:

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Magnetorheological elastomer is a new kind of intelligent material that mainly incorporates micron-sized ferromagnetic particles into a polymer. A dynamic vibration absorber that is based on the controllable shear modulus of magnetorheological elastomer is widely used in vibration systems. In the study, a flexible carbody model with a magnetorheological elastomer dynamic vibration absorber is established. A design method of a semiactive dynamic vibration absorber that is based on magnetorheological elastomer is introduced, and the operational principle of the semiactive dynamic vibration absorber is also discussed. To improve the vibration absorption performance of the magnetorheological elastomer dynamic vibration absorber, via multiple regression analysis, the optimal design frequency expressions for both the rigid vibration and the elastic vibration of the carbody are fitted. Parameter determination for the magnetorheological elastomer dynamic vibration absorber is investigated in detail. Then, the effects on the rigid vibration and the elastic vibration with the magnetorheological elastomer vibration absorber both with the passive vibration absorber and without a vibration absorber are analyzed. Finally, Sperling’s riding index is used to evaluate the feasibility and the performance of the magnetorheological elastomer dynamic vibration absorber in a practical application. The results demonstrate that the vibration of the carbody can be effectively reduced by using the magnetorheological elastomer dynamic vibration absorber instead of the dynamic vibration absorber without the magnetorheological elastomer. The magnetorheological elastomer dynamic vibration absorber that is modified by the optimum frequency provides superior vibration reduction performance and improves the riding quality of the railway vehicle.

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“…6–11 The application of DVA theory has already been proved to be a reliable and effective way to reduce the structural vibration at certain frequencies. 12–17 In this paper, the theory of DVA is applied to reduce the carbody abnormal pitching motion of low-floor railway train around 8 Hz. The basic principle of the DVA is to attach a substructure to the low-floor railway train in order to suppress the vibrations in the expected frequency field by changing the parameters or the relationship of the two vibration systems.…”

Section: Research Backgroundmentioning

confidence: 99%

Reduction of vertical abnormal vibration in carbodies of low-floor railway trains by using a dynamic vibration absorber

Wang

Zeng

Lai

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part F:

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A field test on the dynamic performance of a 100% low-floor railway train with five cars was conducted, and a vertical vibration at around 8 Hz was mainly studied for the background of the research. The vibration around 8 Hz, defined as the abnormal vertical vibration, was proved to be due to the pitching motion of the carbodies, which significantly affected the dynamic performance of the vehicle with a maximum increase of 0.309 in the vertical Sperling index. The dynamic vibration absorber theory was applied to reduce the abnormal vibration of carbodies to around 8 Hz by building a vertical mathematic model and a three-dimensional dynamical simulation model. The results of the theoretical analysis show that the stiffness of the articulated device between carbodies is the reason for the pitching motions at around 8 Hz, and the stiffness significantly affects the main frequency of the vertical vibration of carbodies. What’s more, the application of dynamic vibration absorber theory on low-floor railway trains can reduce the vertical abnormal vibration effectively. Yet, reasonable suspension parameters are needed; otherwise, the vibration of carbodies, including the mass ratio, the suspension frequency, the damping ratio, and the suspended location would be aggravated. Optimal suspension parameters of the dynamic vibration absorber system were used in the simulation model, and the result shows a good agreement with the numerical results; the attached dynamic vibration absorber system on carbodies significantly reduces the vibration of carbodies at around 8 Hz. However, it should be noted that the dynamic vibration absorber is only effective at high-speed stage (beyond 40 km/h) where the pitching motion of carbodies is obvious; this conclusion is consistent with the results of the field test.

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Flexible vibration analysis for car body of high-speed EMU

Cited by 55 publications

References 9 publications

Effect of the tank car thickness on the nonlinear dynamics of railroad vehicles

Effect of the tank car thickness on the nonlinear dynamics of railroad vehicles

Study on the vibration suppression of a flexible carbody for urban railway vehicles with a magnetorheological elastomer-based dynamic vibration absorber

Reduction of vertical abnormal vibration in carbodies of low-floor railway trains by using a dynamic vibration absorber

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