Development of Viscoelastic Multi-Body Simulation and Impact Response Analysis of a Ballasted Railway Track under Cyclic Loading

Abstract

Simulation of a large number of deformable bodies is often difficult because complex high-level modeling is required to address both multi-body contact and viscoelastic deformation. This necessitates the combined use of a discrete element method (DEM) and a finite element method (FEM). In this study, a quadruple discrete element method (QDEM) was developed for dynamic analysis of viscoelastic materials using a simpler algorithm compared to the standard FEM. QDEM easily incorporates the contact algorithm used in DEM. As the first step toward multi-body simulation, the fundamental performance of QDEM was investigated for viscoelastic analysis. The amplitude and frequency of cantilever elastic vibration were nearly equal to those obtained by the standard FEM. A comparison of creep recovery tests with an analytical solution showed good agreement between them. In addition, good correlation between the attenuation degree and the real physical viscosity was confirmed for viscoelastic vibration analysis. Therefore, the high accuracy of QDEM in the fundamental analysis of infinitesimal viscoelastic deformations was verified. Finally, the impact response of a ballast and sleeper under cyclic loading on a railway track was analyzed using QDEM as an application of deformable multi-body dynamics. The results showed that the vibration of the ballasted track was qualitatively in good agreement with the actual measurements. Moreover, the ballast layer with high friction reduced the ballasted track deterioration. This study suggests that QDEM, as an alternative to DEM and FEM, can provide deeper insights into the contact dynamics of a large number of deformable bodies.

New Insights into the Short Pitch Corrugation Enigma Based on 3D-FE Coupled Dynamic Vehicle-Track Modeling of Frictional Rolling Contact

“…The vehicle-track structural dynamics are directly coupled to the wheel-rail contact mechanics through the continuum treatment of the wheel and rail in the structure. The simulation of continuum mechanics has been reported to play "an important role in structural analysis" [25] and allows the instantaneous mutual influence of the contact mechanics and the structural mechanics to be simulated. This approach was presented in [26] to analyze the phase relationship between the given corrugation and the resulting periodic wear, and a similar approach was employed to study corrugation in a high-speed railway [27].…”

An Analytical Solution for Non-Linear Viscoelastic Impact

“…The authors mention that the model is applicable only for quasi-elastic collisions (c r > 0.9). Applications of multi-body models are suitable for different domains of engineering, from classical parts of machine elements [40,41], to granular [34,35] and powder materials [42,43] or biomechanics and robotics [44][45][46].…”

Numerical analysis of the embedded track structure under mixed traffic load

“…Hence, we put forward an optimum range of elastic modulus to improving the stability of embedded rail track. The embedded track is symmetrical along the center line [8], so the track is divided along the longitudinal symmetry center plane, and the 1/2 track structure is taken as the calculation model [5]. The track structure is shown in figure 1.…”