Testing and Modelling of Elastomeric Element for an Embedded Rail System

Abstract

Modelling of elastomeric elements of railway components, able to represent stiffness and damping characteristics in a wide frequency range, is fundamental for simulating the train–track dynamic interaction, covering issues such as rail deflection as well as transmitted forces and higher frequency phenomena such as short pitch corrugation. In this paper, a modified non-linear Zener model is adopted to represent the dependences of stiffness and damping of the rail fastening, made of elastomeric material, of a reference Embedded Rail System (ERS) on the static preload and frequency of its deformation. In order to obtain a reliable model, a proper laboratory test set-up is built, considering sensitivity and frequency response issues. The equivalent stiffness and damping of the elastomeric element are experimentally characterised with force-controlled mono-harmonic tests at different frequencies and under various static preloads. The parameters of the non-linear Zener model are identified by the experimental equivalent stiffness and damping. The identified model correctly reproduces the frequency- and preload-dependent dynamic properties of the elastomeric material. The model is verified to be able to predict the dynamic behaviour of the elastomeric element through the comparison between the numerically simulated and the experimentally measured reaction force to a given deformation time history. Time domain simulations with the model of the reference ERS demonstrate that the modelled frequency- and preload-dependent stiffness and damping of the elastomeric material make a clear difference in the transient and steady-state response of the system when distant frequency contributions are involved.

Measurement, Modeling, and Analysis of the Dynamic Properties of Resilient Elements Used for Vibration Isolation

“…(4a). Li et al [79] performed laboratory tests on a full-size 750 mm long sample of an embedded rail system and used the driving-point method to determine the vertical dynamic stiffness at frequencies up to 20 Hz. At low frequencies (typically f<200 Hz [24]), the dynamic transfer stiffness is approximately equal to the dynamic point stiffness,…”

“…a stiffening due to increased cross-sectional area of the preloaded rubber isolator [108]. For example, the preload dependence of rubber elements used in railway tracks [36], [69], [75], [79], [129] and vehicles [70], [71], [130] have been examined, assuming the amplitude dependence could be neglected.…”

Implementation and analysis of viscoelastic damping in a 2D + 1D model of railway track vibrations

“…In this minimization we adopted ζ n = 1 [33]. Concerning the Zener model, we used the parameters values from reference [38], that are k 1 = 62×10 6 N/m, k 2 = 9.6 × 10 6 N/m and c 2 = 7 × 10 5 Ns/m for its dissipation coefficient, with ρ 2 = c 2 /k 2 yielding 0.073.…”

Evaluation of Structural Stresses of Mountain-Embedded Railway Systems

“…So far, research related to ERSs has included analyses of the various factors, specifically, wheel-rail impact in an embedded rail system [4], the dynamic behavior between the railway track system and vehicles [5,6], and the optimized cross-section of the ERS track and its vertical stiffness [7]. In addition, the attachment performance and modeling methods used for the structural analysis of synthetic resin materials for fastening rails to concrete panels have been studied [8,9].…”