Vector Form Intrinsic Finite Element Method for Stochastic Analysis of Train–Track–Bridge Coupling System

2021 ◽  
Author(s):  
Su-Mei Wang ◽  
Yi-Qing Ni ◽  
Yuan-Feng Duan ◽  
Jong-Dar Yau
Keyword(s):  
Finite Element ◽  
Interaction Model ◽  
Stochastic Dynamic ◽  
Train Track ◽  
Vector Form ◽  
Gaussian Integration ◽  
Coupling System ◽  
Rail Irregularity ◽  
Stochastic Dynamic Analysis ◽  
Track Bridge

In this paper, a train–track–bridge (TTB) interaction model that can account for coach-coupler effect is presented for stochastic dynamic analysis of a train traveling over a bridge. Based on the vector form intrinsic finite element (VFIFE) method, both the bridge and non-ballasted track are discretized into a set of mass particles connected by massless beam elements, in which the fasteners that fixed the tracks on the bridge deck are modeled as a series of linear spring-dashpot units. The multi-body train car is regarded as seven mass particles (1 for car body, 2 for bogies and 4 for wheelsets) connected by parallel spring-dashpot units. Considering the random nature of rail irregularities, the Karhunen–Loéve expansion (KLE) method is used to simulate the vertical profile of the tracks. To calculate the mean and standard deviation of the stochastic response of the TTB system, the point estimated method (PEM) based on the Gaussian integration and dimension reduction method is adopted. The proposed VFIFE–TTB interaction model is then applied to stochastic resonance analyses of a train moving on a bridge. It is shown that the present VFIFE–TTB model is able to analyze the dynamic interaction of the TTB system simply and efficiently. The influence of rail irregularity-induced stochastic vibration on the train and bridge would become significant once the resonant vibration takes place on the TTB system.

Stochastic Dynamic Analysis of Structures with Spatially Uncertain Material Parameters

2014 ◽  
Vol 14 (08) ◽  
pp. 1440029 ◽  
Author(s):  
Kheirollah Sepahvand ◽  
Steffen Marburg
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Polynomial Chaos ◽  
Element Model ◽  
Stochastic Dynamic ◽  
Stochastic Field ◽  
Structural Dynamic ◽  
Material Parameters ◽  
Material Uncertainties ◽  
Stochastic Dynamic Analysis

This paper investigates the uncertainty quantification in structural dynamic problems with spatially random variation in material and damping parameters. Uncertain and locally varying material parameters are represented as stochastic field by means of the Karhunen–Loève (KL) expansion. The stiffness and damping properties of the structure are considered uncertain. Stochastic finite element of structural modal analysis is performed in which modal responses are represented using the generalized polynomial chaos (gPC) expansion. Knowing the KL expansions of the random parameters, the nonintrusive technique is employed on a set of random collocation points where the structure deterministic finite element model is executed to estimate the unknown coefficients of the polynomial chaos expansions. A numerical case study is presented for a cantilever beam with random Young's modulus involving spatial variation. The proportional damping constants are estimated from the experimental modal analysis. The expected value, standard deviation, and probability distribution of the random eigenfrequencies and the damping ratios are evaluated. The results show high accuracy compared to the Monte-Carlo (MC) simulations with 3000 realizations. It is also demonstrated that the eigenfrequencies and the damping ratios are equally affected from material uncertainties.

Dynamic Response of High-Speed Train-Track-Bridge Coupling System Subjected to Simultaneous Wind and Rain

2021 ◽  
pp. 2150161
Author(s):  
Hongye Gou ◽  
Wenhao Li ◽  
Siqing Zhou ◽  
Yi Bao ◽  
Tianqi Zhao ◽  
...  
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Simultaneous Action ◽  
High Speed Train ◽  
Train Track ◽  
Safe Operation ◽  
Coupling System ◽  
High Speed Trains ◽  
Track Bridge ◽  
Bridge System

The Lanzhou-Xinjiang High-speed Railway runs through a region of over 500[Formula: see text]km that is amenable to frequent winds. The strong wind and rainfall pose a great threat to the safe operation of high-speed trains. To tackle the aforementioned climate challenges, this paper investigates the dynamic response of the high-speed train-track-bridge coupling system under the simultaneous action of winds and rains for the safe operation of trains. Specifically, there are four main objectives: (1) to develop a finite element model to analyze the dynamic response of the train-track-bridge system in windy and raining conditions; (2) to investigate the aerodynamic loads posed to the train-track-bridge system by winds and rains; (3) to evaluate the effects of wind speed and rainfall intensity on the train-track-bridge system; and (4) to assess the safety of trains at different train speeds and under various wind-rain conditions. To this end, this paper first establishes a train-track-bridge model via ANSYS and SIMPACK co-simulation and the aerodynamics models of the high-speed train and bridge through FLUENT to form a safety analysis system for high-speed trains running on the bridge under the wind-rain conditions. Then, the response of the train-track-bridge system under different wind speeds and rainfall intensities is studied. The results show that the effects of winds and rains are coupled. The rule of variation for the train dynamic response with respect to various wind and rain conditions is established, with practical suggestions provided for control of the safe operation of high-speed trains.

Dynamic Performance of the LMS Maglev Train–Track–Bridge System Under Uneven Settlement for Two Typical Bridges

2020 ◽  
pp. 2150006
Author(s):  
Dangxiong Wang ◽  
Xiaozhen Li ◽  
Ziyan Wu
Keyword(s):  
Numerical Model ◽  
Dynamic Performance ◽  
Interaction Model ◽  
Dynamic Interaction ◽  
Dynamic Responses ◽  
Train Track ◽  
Maglev Train ◽  
Medium Speed ◽  
Track Bridge ◽  
Bridge System

To investigate the dynamic performance of the low-to-medium-speed (LMS) maglev train and bridge system under uneven ground settlement, a refined vertical dynamic interaction model of the LMS maglev train–track–bridge system with uneven settlement is proposed. Firstly, the numerical model is verified based on the field test. Secondly, the dynamic performances of the system induced by uneven settlements are numerically analyzed. Furthermore, numerical studies are carried out to investigate the effect of various uneven settlement types, to compare the performances of the two typical bridges, and to assess the contribution of the F-rail in the presence of uneven settlement. The results show that uneven settlement has a significant enlargement effect on the dynamic responses of the car body and levitation module, but a very weak influence on the bridge. Both the patterns of uneven settlement and bridge types significantly affect the dynamic response of the maglev train to various levels. The numerical model excluding the track structure will overestimate the dynamic responses of the levitation module. It is suggested that the dynamic interaction model for the maglev train–track–bridge system be selected to simulate the influence of uneven settlement for better accuracy.

Validation of a vertical train–track–bridge dynamic interaction model based on limited experimental data

2019 ◽  
Vol 16 (1) ◽  
pp. 181-201 ◽  
Author(s):  
Ladislao R. Ticona Melo ◽  
Diogo Ribeiro ◽  
Rui Calçada ◽  
Túlio N. Bittencourt
Keyword(s):  
Experimental Data ◽  
Interaction Model ◽  
Dynamic Interaction ◽  
Train Track ◽  
Model Based ◽  
Track Bridge

Effects of Pier Deformation on Train Operations within High-Speed Railway Ballastless Track–Bridge Systems

2018 ◽  
Vol 2672 (10) ◽  
pp. 96-105 ◽  
Author(s):  
De Zhang ◽  
Junhua Xiao ◽  
Xiao Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Element Model ◽  
Lateral Deformation ◽  
Train Track ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Train Operation ◽  
Track Bridge

The deformation of a bridge foundation (i.e. pier) for a ballastless track of a high-speed railway may cause additional irregularities within the track, thereby affecting train operation. By using a unit slab ballastless track bridge system as the research object, this study built a finite element model and a train–track dynamic interaction model. The additional rail deformation caused by the vertical or lateral deformation of a bridge pier was calculated by the finite element model, and then the effects on train operation due to the additional rail deformation were analyzed by the train–track dynamic model. It was found that the lateral deformation of a single pier should be of the most concern for the management and control of a high-speed railway. Specifically, when a pier suffered settlement and lateral deformation concurrently, the evaluation indices of train operation were primarily affected by the magnitude of the lateral deformation, and were only slightly affected by the settlement.

A Practical Wheel-Rail Interaction Element for Modeling Vehicle-Track-Bridge Systems

2019 ◽  
Vol 19 (02) ◽  
pp. 1950011 ◽  
Author(s):  
Quan Gu ◽  
Yongdou Liu ◽  
Wei Guo ◽  
Weiquan Li ◽  
Zhiwu Yu ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Responses ◽  
Software Framework ◽  
Fe Model ◽  
Simply Supported ◽  
Interaction Element ◽  
Rail Irregularity ◽  
Rail Irregularities ◽  
Nodal Displacements ◽  
Track Bridge

A novel practical element is presented for simulating the vertical wheel-rail interaction (WRI) of vehicle-track-bridge (VTB) coupling systems. The WRI is time- and location-varying, which makes the simulation of the VTB system complicated. The new element simulates the WRI using a location dependent internal resisting force, which enables the finite element (FE) model of the VTB system to remain unchanged in analysis. This element is capable of simulating the nonlinear WRI, the rail irregularity and the ‘additional’ displacement of the rail. The ‘additional’ displacement is the extra displacement caused by the WRI besides that interpolated from the element nodal displacements, which is usually ignored by existing models, but may be non-negligible in some cases. The WRI element is implemented into a general FE software framework, OpenSees, and verified by the dynamic analysis of a simply-supported beam subjected to a moving sprung mass. Furthermore, a realistic VTB system with a moving four-wheel vehicle is investigated to evaluate the cases where the additional displacement and nonlinear WRI should be considered. Finally, using another realistic VTB system subjected to rail irregularities and earthquakes, the effects of rail irregularity and earthquake on the dynamic responses of the WRI system are studied and compared.

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