Modeling Dynamic Frequency Response on Slab Track of Shinkansen Railway Based on Finite Element Method

Majid Gholizadeh,Farhad Hadadi,Iman Aghayan,Ilaria Venanzi

doi:10.1155/2022/9574243

Abstract

The use of slab tracks in lieu of ballast tracks has introduced new dimensions in track dynamics in high-speed railways. To improve the performance of slab tracks under dynamic frequency responses caused by loads on the Shinkansen railway, the present study aimed to investigate the effect of mechanical properties of track components, including the elasticity modulus and thickness on the resonance frequency of the vertical dynamic responses using the finite element method. Such responses included receptance and decay rate in the asphalt bearing layer (ABL), hydraulically bonded layer (HBL), and concrete bearing layer (CBL). In addition, the study sought to select the optimal layer as an effective layer in the view of reducing the resonance frequency of dynamic responses in comparison with the general model. Based on the data regarding the effects of elasticity modulus and thickness of slab track layers on the resonance of the dynamic frequency responses under the amplitude loads, by changing the load from 20 to 25 tons over the slab track, the receptance under the modulus and thickness change increased up to 34 and 29%. Moreover, the decay rate under the modulus and thickness change increased up to 31 and 37%. Accordingly, by increasing the load amplitude, the CBL and HBL showed lower dynamic responses than other layers. Thus, CBL and HBL were selected as the optimum layers for improving the performance of the slab track of the Shinkansen railway.

Highlights

Investigating the effect of dynamic response at low frequency is important
The current research seeks to select the most effective layer throughout concrete bearing layer (CBL), hydraulically bonded layer (HBL), and asphalt bearing layer (ABL) compared with the general model regarding the two vertical dynamic responses such as receptance and decay rate by elasticity modulus and thickness changes and various vehicle loading using the finite element method (FEM)
To investigate the modulus and thickness effects of Shinkansen slab track components such as CBL, HBL, and ABL on the resonance frequency using FEM, first, model specifications and material characteristics are defined in ABAQUS software, followed by using the two concepts of receptance and track decay rate. e frequency response is used for the validation according to the method of Craig and Kurdila. en, the modeling of the slab track is considered based on the Euler–Bernoulli beam theory under the harmonic loading of the unit with a length of 30 m [49]. e following sections describe the characteristics of the Shinkansen slab track, dynamic frequency responses, and the modeling procedure

Summary

Introduction

Investigating the effect of dynamic response at low frequency is important. At low-frequency vibration, the environmental problem is the main concern of the track structure for highspeed railways [1, 2]. When a train runs on a track at low frequencies, the interaction force between wheels and rails generates vibration in dynamic frequency responses, including receptance and decay rate on the track structure in high-speed lines. Other studies showed that under lowfrequency vibration, the dynamic responses including receptance and decay rate on the slab track reach their critical regions in which the performance of slab track decreases. The effect of low-frequency ranges between 1 and 15 Hz on the growth of the resonance frequency of decay rate, and receptance and their amplitudes go up as frequency is decreased, and vice versa [5,6,7]. Slab tracks in high-speed railways have increased over time [8, 9]

Methods

Results

Conclusion