Influence of Suspended Equipment on the Carbody Vertical Vibration Behaviour of High-Speed Railway Vehicles

Abstract

The equipment mounted on the carbody chassis of the railway vehicles is a critical component of the vehicle in terms of ride comfort. The reason for that is their large mass, able to visibly influence the vibrations mode of the carbody. The paper examines the influence of the equipment upon the mode of vertical vibrations of the carbody in the high-speed vehicles, reached on the basis of the frequency response functions of the acceleration in three carbody reference points -at the centre and above the bogies. These functions are derived from the numerical simulations developed on a rigid-flexible coupled model, with seven degrees of freedom. As a rule, the results herein prove the influence of the equipment mounting mode (rigid or elastic), along with the speed regime, upon the level of vibrations in the carbody reference points, at the resonance frequency of the symmetrical bending mode. Similarly, it is also demonstrated how the equipment mass and the damping degree of the suspension system affect the level of the vibrations in the carbody.

Numerical study on the influence of suspended equipments on the ride comfort in high speed railway vehicles

“…The motions of each body can be numerically solved using compiled MATLAB codes. For the model with one equipment, the selection will be for the equipment with the largest mass (m e1 = m e = 3960 kg), mounted at the centre of the carbody (l e1 = l e = L c /2), according to the usual models in the literature review [2,7,9,14,16].…”

“…bounce, pitch and flexible bending modes) influencing the vertical ride comfort are included. [2,7,9,14,16]. A more complex representation of the carbody would use 3D rigid-flexible coupled models built in compliance with the multi body system (MBS) theory and the finite element method (FEM) [3,6,7,8,12,17].…”

Suspension parameter design of underframe equipment considering series stiffness of shock absorber

“…Figure 1 shows the vertical vibration model of vehicle–equipment coupling system. 7,20 The model consists of an elastic carbody, an underframe suspended equipment, two bogies, and four wheelsets. The carbody is considered as a uniform Euler–Bernoulli beam, the primary and secondary suspensions of the railway vehicle are realized by Kelvin–Voigt-type systems, and the original scheme for the underframe suspension system uses the Kelvin–Voigt type.…”

“…4–6 Equipments such as traction transformers, traction converters, and pantograph compressors are installed in the carbody underframe; the weight of these equipment ranges from tens kilograms to several tons, and some even with their own excitation source. 7 The design of the suspension system became a major concern and a research hotspot not only for ride comfort and driving safety but also for energy consumption. 8,9 In order to prevent the spread of noise and suppress the vibration level of the carbody, the best solution for these carbody underframe equipment is still the focus of many scholars.…”

Study on semi-active suspension applied on carbody underneath suspended system of high-speed railway vehicle

“…It can greatly reduce the weight of the carbody, which can reduce the demand for vehicle traction, but also decrease its stiffness, generating an increase in carbody flexible vibration (Gong et al, 2017; Tomioka and Takigami, 2010). In addition, to attain the requirement of higher speed of railway vehicle, the traction transformer and other electrical equipment is suspended and installed on the chassis of the carbody with a power-dispersive traction mode, causing coupling vibration between the vehicle carbody and the suspended equipment, potentially significantly impacting passenger ride comfort (Dumitriu, 2016; Tomioka et al, 2017; Zhou et al, 2009). Figure 1 shows the distribution diagram of the suspended equipment on a high-speed railway vehicle, which is installed under the carbody.…”