The commercial operation of the bullet train in 1964 in Japan marked the beginning of a new era for high-speed railways. Because of the huge amount of kinetic energy carried at high speeds, a train may interact significantly with the bridge and even resonate with it under certain circumstances. Equally important is the riding comfort of the train cars, which relates closely to the maneuverability of the train during its passage over the bridge at high speeds.This book is unique in that it is devoted entirely to the interaction between the supporting bridges and moving trains, the so-called vehicle-bridge interaction (VBI). Finite element procedures have been developed to treat interaction problems of various complexities, while the analytical solutions established for some typical problems are helpful for identifying the key parameters involved. Besides, some field tests were conducted to verify the theories established.This book provides an up-to-date coverage of research conducted on various aspects of the VBI problems. Using the series of VBI elements derived, the authors study a number of frontier problems, including the impact response of bridges with elastic bearings, the dynamic response of curved beam to moving centrifugal forces, the stability and derailment of trains moving over bridges shaken by earthquakes, the impact response of two trains crossing on a bridge, the steady-state response of trains moving over elevated bridges, and so on.

The main objective of this book is to establish efficient numerical models within the framework of finite element method to solve the dynamic response of the Vehicle-Bridge Interaction (VBI) systems for vehicles moving with constant velocity or with acceleration. For vehicles with constant velocity, the dynamic condensation method is applied to reduce the vehicle DOFs to the VBI element. VBI element refers to bridge beam elements that are in direct contact with wheels of the vehicles traversing the bridge. A new formulation is proposed for the mass, damping, and stiffness of the VBI element considering new formulation for the contact points. For vehicles experiencing sudden deceleration with sliding, external forces resulting from vehicle horizontal deceleration are numerically formulated in a matrix form as the function of vertical contact forces. By defining a new parameter called acceleration parameter with particular characteristics, the contact force formula is reformulated. Consequently, a new formulation for the VBI element containing the effect of vehicle acceleration is developed.

The commercial operation of the bullet train in 1964 in Japan markedthe beginning of a new era for high-speed railways. Because of thehuge amount of kinetic energy carried at high speeds, a train mayinteract significantly with the bridge and even resonate with it undercertain circumstances. Equally important is the riding comfort of thetrain cars, which relates closely to the maneuverability of the trainduring its passage over the bridge at high speeds.

Vehicle-bridge interaction happens all the time on roadway bridges and this interaction performance carries much useful information. On one hand, while vehicles are traditionally viewed as loads for bridges, they can also be deemed as sensors for bridges' structural response. On the other hand, while bridges are traditionally viewed as carriers for vehicle weight, they can also be deemed as scales that can weigh the vehicle loads. Based on these observations, a broad area of studies based on the vehicle-bridge interaction have been conducted in the authors' research group. Understanding the vehicle and bridge interaction can help develop strategies for bridge condition assessment, bridge design, and bridge maintenance, as well as develop insight for new research needs.This book documents fundamental knowledge, new developments, and state-of-the-art applications related to vehicle-bridge interactions. It thus provides useful information for graduate students and researchers and therefore straddles the gap between theoretical research and practical applications.

This book systematically presents the theory, numerical implementation, field experiments and practical engineering applications of the ‘Vehicle–Track Coupled Dynamics’. Representing a radical departure from classic vehicle system dynamics and track dynamics, the vehicle–track coupled dynamics theory considers the vehicle and track as one interactive and integrated system coupled through wheel–rail interaction. This new theory enables a more comprehensive and accurate solution to the train–track dynamic interaction problem which is a fundamental and important research topic in railway transportation system, especially for the rapidly developed high-speed and heavy-haul railways. It has been widely applied in practical railway engineering. Dr. Wanming Zhai is a Chair Professor of Railway Engineering at Southwest Jiaotong University, where he is also chairman of the Academic Committee and Director of the Train and Track Research Institute. He is a member of the Chinese Academy of Sciences and one of the leading scientists in railway system dynamics. Professor Zhai is Editor-in-Chief of both the International Journal of Rail Transportation, published by Taylor & Francis Group, and the Journal of Modern Transportation, published by Springer. In addition, he is a trustee of the International Association for Vehicle System Dynamics, Vice President of the Chinese Society of Theoretical and Applied Mechanics, and Vice President of the Chinese Society for Vibration Engineering. /div

This dissertation aimed to devise predictive tools for analyzing various support structuresof a high-speed rail (HSR) system to support their design under operational and seismic loads. The detailed objectives are (i) to implement a vehicle-bridge-interaction (VBI) method for analyzing coupled train-track coupled dynamics, (ii) to develop a finite ele- ment (FE) approach for analyzing the interaction of a local domain with a moving load (as the load enters, traverses, and leaves the local domain) based on the application of Perfectly-Matched-Layers (PMLs) and the Domain Reduction Method (DRM), and (iii) to carry out various application studies that explore the interaction of moving loads with flexible or buried structures using the tools developed to verify them and to demonstrate their utility. The methods described above are implemented in commercial finite element analysis software ABAQUS through a combination of MATLAB codes and ABAQUS' user-defined element (UEL) subroutine interface. These implementations were carried out to enhance the potential impact of the analysis tools developed as part of this dissertation and broaden their applicability. The computational efficiency afforded by the developed tools obviates the need to carry out simulations with large finite element domains (through the use of PML+DRM and proper injection of boundary conditions emanating from far- field (inbound vehicle and/or seismic) loads at the truncated domain boundaries) and to develop explicit multi-degree-of-freedom dynamic models of the considered vehicles.

[Truncated abstract] Many load rating methods have been developed in recent years to evaluate the safety and serviceability of existing bridges. In general, the rating of a bridge is carried out by comparing the factored live load effects of nominated rating vehicles with the available bridge capacity. Therefore, accurate and practical approaches to calculate the live load on bridges resulting from moving vehicles and to estimate the bridge load carrying capacity are essential for bridge load rating. The research described in this thesis aims to develop a load rating procedure for accurately estimating the load carrying capacity of existing bridges. It involves three main parts of work. First, to obtain a reliable Finite Element (FE) model of the bridge under the current condition, FE model updating analysis is carried out to refine the bridge model based on the field measured vibration data. Second, detailed static nonlinear Finite Element Analysis (FEA) based on the updated FE model is carried out to determine the bridge load carrying capacity. In this part, the dynamic vehicle-bridge interaction is only approximately modelled by using the code specified Dynamic Amplification Factor (DAF) or Dynamic Load Coefficient (DLC). In the third part, to more precisely model dynamic vehicle-bridge interaction and predict the DAF, nonlinear stochastic dynamic response analysis of an equivalent hysteretic Single Degree of Freedom (SDOF) system subjected to a non-stationary non-zero mean excitation are carried out. The equivalent SDOF system is derived from the actual bridge conditions. The advantages of these approaches are that they can model the actual current condition of a bridge by applying the model updating method and take into account the effects of road surface roughness, single or multiple vehicles-bridge interaction and material nonlinearity of prestressed or reinforced concrete. ... At last, based on the principle of equivalent dissipated energy, the resulting load-displacement relationship may be simplified as a bilinear hysteretic model which defines the stiffness of the equivalent SDOF system. The excitation force of the equivalent SDOF system is a non-stationary stochastic process with non-zero mean, which is caused by the vehicle weight and vehicle-bridge interaction. This thesis presents a novel approach to the evolutionary spectral analysis for the random response of a coupled vehicle-bridge system. The proposed method is capable of taking into account the random characteristics of vehicle-bridge interaction induced by road surface roughness and effect of multiple vehicles-bridge interaction. In addition, this method allows each vehicle to be modelled using a mass-spring-damper system with 4 Degrees Of Freedom (DOF). The resulting stochastic dynamic interaction force can be transformed to an excitation force of the equivalent SDOF system by applying the principle of virtual work. Once the mass, damping, stiffness and excitation force of the equivalent SDOF system are determined, the equation of motion of this SDOF system can be solved using the equivalent linearization method. The entire proposed rating procedure is applied to rating of a practical bridge located in the Shire of Roebourne in Western Australia. Also, parametric studies are conducted in this research to investigate the effects of the length ratio, vehicle to bridge frequency ratio, bridge damping ratio, vehicle to bridge mass ratio, vehicle speed, vehicle number and road surface condition on the DAF and DLC.