Train-bridge Interaction Research Articles

Train–bridge interaction – a review and discussion of key model parameters

Research in the field of train–bridge interaction is reviewed, with a particular focus on the vertical dynamic response of the bridge. The most influential system parameters are identified and discussed, providing a basis from which to establish an appropriate degree of complexity in train and track modelling. A two-level factorial experiment is presented. This is used to highlight the relative influence of train–bridge interaction in the train–bridge model, compared with variations in other key parameters. We distinguish those parameter combinations in the train–bridge system that lead to a significant reduction in bridge response due to the train–bridge interaction. The present survey fills an important gap in our existing knowledge by synthesising conclusions from the vast literature on train–bridge interaction. Moreover, the knowledge is related to the European design code’s guidelines for dynamic bridge analysis. The conclusions are summarised to give a rough guidance on modelling choices for train–bridge interaction systems.

Energy Harvesting from Train-Induced Response in Bridges

The integration of large infrastructure with energy-harvesting systems is a growing field with potentially new and important applications. The possibility of energy harvesting from ambient vibration of bridges is a new field in this regard. This paper investigates the feasibility of energy harvesting for a number of trains considering their passage over a bridge. The power that can be derived from an energy-harvesting device due to a train crossing a bridge at different speeds is compared against typical demands of small wireless devices and is found to be adequate for powering such devices. These estimates of harvested energy also relate to the individual signatures of trains. In this work, the modeled dynamic responses of a bridge traversed by trains are compared against full-scale experimental analysis of train–bridge interactions. A potential application in structural health monitoring (SHM) using energy harvesting has also been demonstrated and compared with laboratory experimental data. Consistent and monotonic damage calibration curves have been constructed using estimated harvested energy.

Statistical screening of modelling alternatives in train–bridge interaction systems

The effect of parameter variations in railway bridges subjected to train loads has been evaluated within the framework of a two-level factorial experiment. Especially, the influence of train–bridge interaction in comparison to other parameter variations is highlighted. Variations in the system parameters were introduced, corresponding to modelling alternatives considering reasonable uncertainties in a bridge design model. The dynamic effect from a passenger train set has been evaluated at, and away from, resonance in beam bridges of span lengths 6, 12, 24 and 36m. By means of the two-level factorial design, effects from changes in a single parameter, as well as joint effects from simultaneous changes in several parameters, may be evaluated. The effect of including train–bridge interaction through a simple vehicle model as opposed to moving forces was found most distinct at resonance. The effect of the choice of load model was furthermore shown largest for the bridges of span length 24 and 36m, where it was found more influential or comparable to the effect of other system parameter uncertainties. The high influence of the load model may well be attributed to the fact that the natural frequencies of the 24 and 36m bridges are close to the vertical frequency of the primary suspension system of the train. The reduction of response obtained with the train–bridge interaction model are discussed in relation to bridge frequency rather than span length, and compared to the Additional Damping Method given in the European design code.

Assessment of the dynamic and fatigue behaviour of the Panaro railway steel bridge

The functionality maintenance of European infrastructures like bridges is acquiring more and more importance due to the huge economic losses related to the interruption of their regular service. In particular, fatigue represents one of the most common failure modes occurring in steel and steel–concrete composite bridges: most failures in steel structures are related to fracture and fatigue. Railway bridges endure millions of stress cycles during their life and they are expected to be highly vulnerable to such phenomena. Phenomena like ‘vibration induced’ and ‘distortion induced’ fatigue are still partially uncovered by actual design codes and they represent critical aspects for the assessment of existing bridge remaining life and for the design of new bridges. The European research project FADLESS ‘Fatigue damage control and assessment for railways bridges’, funded by the Research Fund for Coal and Steel, aims at defining innovative technical guidelines for the assessment and control of existing and new bridges with regard to fatigue phenomena induced by vibrations and distortions produced by train passages. The project combines experimental and numerical techniques to study fatigue cracking induced by vibration and distortion phenomena taking into account the dynamic train–bridge interaction effects and the actual traffic spectra on European railway lines. In the present paper, preliminary analyses performed on the Italian case study, the Panaro Bridge, are being reported upon. Results obtained by standard fatigue assessment according to Eurocode rules were compared with the actual fatigue cracks found in the deck secondary components. A preliminary critical review of adopted fatigue assessment methodologies was carried out. Moreover, experimental tests were designed and performed on the bridge in order to identify global and local vibration modes and to evaluate the strain time-histories under train passages of critical details. Finally, experimental global/local mode shapes were compared to numerical results from the preliminary FE bridge model.

Dynamic responses of Tsing Ma Bridge and running safety of trains subjected to Typhoon York

A three-dimensional wind–train–bridge interaction model, which consists of a spatial finite element bridge model, a train model composed of eight 4-axle identical coaches of 27 degrees of freedom, and a turbulent wind model is established for the Tsing Ma suspension bridge located in Hong Kong during Typhoon York. The acceleration and displacement responses of the bridge induced by turbulent winds and running trains are computed and compared with the responses measured from the field. The comparison is found to be satisfactory in general. The runnability of the train passing through the Tsing Ma Bridge at different speeds is researched under turbulent winds. Then the threshold curve of wind velocity for ensuring the running safety of the train in the bridge deck is proposed, from which the allowable train speed at different wind velocities can be determined.

PolyVinyliDene Fluoride (PVDF) Material Based Energy Harvesting from Train and Damaged Bridge Interaction

This paper investigates the potential use of PolyVinyliDene Fluoride (PVDF) for the purposes of damage detection for infrastructural elements, primarily for bridge elements. PVDF based sensors have been created and characterised in the laboratory in this regard. Finite element analysis of vehicle-bridge interactions with varying damage are carried out. The energy harvesting signatures of realistic trains are assessed and quantified for the modelled bridge. The effect of localized damage on the finite element model and its subsequent relationship with energy harvesting from the calibrated PVDF based sensors are investigated using the harvesting signatures of realistic trains. This approach is useful in terms of designing new generation smart bridge structures and for possible retrofit of existing structures. The use of train-bridge interaction ensures that the damage detection is carried out while the bridge is under operational conditions. Consequently, there is minimal to no impact on the existing operation of the bridge or the transport network during damage detection. The paper is expected to be useful for practicing engineers and researchers in the field of application of new materials in the next generation of bridge structures.

SEISMIC BEHAVIOR OF STEEL MONORAIL BRIDGES UNDER TRAIN LOAD DURING STRONG EARTHQUAKES

This paper investigated dynamic responses of steel monorail bridges incorporating train-bridge interaction under strong earthquakes. Two types of steel monorail bridges were considered in the study: a conventional type with steel track-girder; an advanced type with composite track-girder and simplified lateral bracing system. During strong earthquakes, monorail train was assumed standing on the track-girder of monorail bridges. Observations through the analytical study showed that considering the monorail train as additional mass rather than a dynamic system in numerical modeling overestimated effect of the train load on seismic performance of monorail bridges. Earlier plastic deformations at the end bracing of the girder system absorbed seismic energy and reduced the stress at the pier base.

Vehicle-Guideway Interaction in Maglev Systems Using a Continuously Coupled, Deformable Model

Magnetic levitation (maglev)-based high-speed trains are one of the most promising means of transport for the near future. To optimize the relatively high investment cost of these networks, engineers need to develop accurate dynamical simulations of the whole, complex maglev system. This involves proper consideration of the interactions between the cars of the train, the levitation frames, and the guideway. In this paper a coupled model for the train-bridge interaction is introduced, which describes the vibrations of the vehicle and the guideway by using deformable Bernoulli-Euler beams continuously connected by springs and viscous dampers. The case of a train arriving on a simply supported guideway is simulated and the results are discussed in detail.

EFFECTS OF RAIL JOINTS AND TRAIN'S CRITICAL SPEED ON THE DYNANIC BEHAVIOR OF BRIDGES

The dynamic amplification of the railway bridges caused by the passage of a train varies according to several factors. Among these factors: defaults of roughness of the rail and its joints, etc. These defects are usually encountered in railways and they influence the dynamics of the vehicle–bridge interaction, whence the importance of this study. In this paper, the defect of rail joint is investigated with train's critical speed. The joints between the rails are modeled by periodic irregularities. The bridge is modeled by a simply supported uniform beam. The train is modeled as a convoy of vehicles moving with a constant speed. The governing equations of motion for the bridge–train interaction system are derived using the Lagrangian formulation and the modal superposition technique. These equations are integrated numerically by applying the Newmark method. This paper presents a computation code in FORTRAN to analyze the effect of the above-mentioned defects on the bridge’s dynamic response. DOI: http://dx.doi.org/10.5755/j01.mech.19.1.3615

Fatigue assessment of a composite railway bridge for high speed trains. Part I: Modeling and fatigue critical details

Steel bridges for high speed trains may sustain excessive fatigue damage due to stronger dynamic effects induced by the increased train speed. Dynamic tests were carried out on a composite railway bridge for high speed trains. A detailed finite element (FE) model of the bridge was established and validated by the dynamic test results. Six types of structural details in the bridge were considered for fatigue evaluation. The stress history of each concerned detail during a single train passage was generated by the validated FE model. The stress spectrum, obtained through Rainflow cycle counting of stress history, was used to calculate the fatigue damage of each detail, based on the detail category specified S–N design curve and the Palmgren–Miner damage rule. Among various structural details, the load carrying fillet weld around the gusset plate of the diagonal bracing at the bridge bearing is predicted to be the most fatigue critical detail. In this paper, a general methodology for determination of fatigue critical details is presented, which can serve as a basis of enhanced fatigue evaluation by using local stress approaches. In “Part II: conditions for which a dynamic analysis is needed” as the continuation of this paper, fatigue assessment will be investigated based on the dynamic stresses predicted by different approaches, i.e. static analysis considering dynamic amplification factor, direct dynamic analysis with a moving load model or a train–bridge interaction model.

Dynamic Analysis of Multispan Viaducts with Weak Coupling between Adjacent Spans

This paper deals with the dynamic analysis of multispan simply supported railway viaducts subjected to moving trains. In the anal- ysis, the Sesia viaduct is considered, which is a composite railway bridge consisting of seven isostatic spans. An experimental analysis shows that the modes of adjacent spans are connected because of the weak coupling through the ballast and rails. In this case, a model of the entire viaduct is needed for an accurate prediction of the dynamic response of the bridge during the passage of the train. To reduce the computational cost, two alternatives are investigated: a single-span model with adjusted boundary conditions and a component mode synthesis (CMS) reduced-order model comprising all seven spans. The two models are subsequently used for dynamic train-bridge interaction analysis. The predicted dynamic responses of the viaduct during a train passage with both models are in good agreement with the experimental results. Com- paredwiththesingle-spanmodel,thecouplingbetweenadjacentspansisbetterrepresentedbytheCMSmodeloftheentireviaduct.Inpractical engineering design, however, the single-span model with adjusted boundary conditions can be used to obtain a reasonably good representation of the dynamic behavior of the bridge. DOI: 10.1061/(ASCE)BE.1943-5592.0000476. © 2014 American Society of Civil Engineers. Author keywords: Multispan railway viaduct; Weak coupling; Component mode synthesis; Train-bridge interaction.

Fatigue assessment of a composite railway bridge for high speed trains. Part II: Conditions for which a dynamic analysis is needed

This paper is a continuation of the paper titled “Fatigue assessment of a composite railway bridge for high speed trains-Part I: modeling and fatigue critical details” with the emphasis on conditions for which a dynamic analysis is needed for a fatigue assessment of the bridge. In part I, a fatigue assessment of the Sesia viaduct is performed by using both a static analysis and a dynamic analysis with a moving load model; fatigue damage levels of several concerned details are calculated and the fatigue critical details are identified. It is found that dynamic effects induced by the high speed trains reveal a big influence on the fatigue damage of the bridge. In this paper, conditions under which a dynamic analysis should be considered for the fatigue assessment of a bridge are investigated. Three different alternatives are considered: a static analysis taken into account a dynamic amplification factor, a dynamic analysis with a moving load model, or a dynamic analysis with multi-body models for the train vehicles include the train–bridge interaction effect. The effect of several parameters related to the train and the bridge is studied. The train speed and the mass ratio between the train and the bridge are identified as significant factors that determine the dynamic effect on the fatigue damage of the bridge.

A multidisciplinary approach for fatigue assessment of a steel–concrete high-speed railway bridge on Sesia river

Steel–concrete composite bridge solutions have been more and more exploited in the new high-speed (HS) lines of European railway networks. New design solutions, introduced during a period of quick expansion for railway networks, amplified open problems related to dynamic effects, train–bridge interaction phenomena, fatigue loadings, structural modelling, fatigue life and comfort. In this article, results obtained by long-term dynamic monitoring of Sesia viaduct, a medium span double-box composite bridge of the new Italian HS network, are described and analysed. Structural modal properties were determined in order to evaluate the real-time dynamic behaviour and its correlation with environmental conditions. A suitable numerical procedure was then implemented in order to identify typology, length and velocity of trains crossing the bridge, to evaluate the intensity of deck vertical accelerations as a function of train speed and to obtain a reliable evaluation of real traffic spectra. A final fatigue assessment on welded connections was executed evaluating fatigue spectra by the aforementioned real traffic spectra and assuming S–N curves obtained by suitably executed experimental tests.

열차의 주행속도와 차체연직가속도의 상관관계를 고려한 철도교량의 진동사용성 처짐 한계

In order to get dynamic serviceability of a train travelling on a railway bridge, comfort limits with the deflection of bridge and vertical acceleration on car body are proposed in Eurocode, Shinkansen design criteria, The design guideline of the Honam High-speed railway. The design guideline of the Honam High-speed railway has quoted Eurocode. Therefore it is expected that supplementation of comfort limit of railway bridge according to expansion of span length and the improvement traveling speed of trains in the future would relatively fall behind developed countries in railway. Therefore, in order to secure technological competitiveness in world market, the study was conducted to propose the deflection limit based on vibration serviceability of railway bridges that can consider bridge-train interaction and travelling speed increase. The parameter study and bridge-train dynamic interaction analysis was conducted to figure out the correlation of vertical acceleration on car body and bridge displacement according to the increase in travelling speed. Also, the trend of increasing vertical acceleration on car body according to the increase in travelling speed was confirmed, and the amplification coefficient of vertical acceleration on car body was suggested. And the deflection form and vibration of the bridge were assumed to be in harmonic motion, and transfer function and the amplification coefficient were used to develop the dynamic serviceability deflection limit of the high-speed railway bridge as a formula.

Simulation of the interactions between a train and a long-span cable-stayed bridge using parallel computing with domain decomposition

This paper deals with the use of parallel explicit finite element modeling with domain decomposition for the simulation of long-span cable-stayed bridge–train interactions. A full three-dimensional finite element model of the long-span cable-stayed bridge was created. Parallel computing based on contact balance was utilized to deal with this large-scale numerical simulation problem. Bridge–train interaction simulation was performed on a Dawning 4000A supercomputer using the finite element code LS-DYNA 971 optimized to run on parallel computers. The dynamic response of the cable-stayed bridge and the effect of different domain decomposition strategies on bridge–train simulation computing efficiency were investigated. The results show the numerical scalability of this algorithm which could also be used to guide the design of long-span cable-stayed bridges.

Dynamical identification and modelling of steel–concrete composite high-speed railway bridges

In the last few years, the construction of new high-speed (HS) railways across Europe, as well as in many other countries, has required many different bridges and viaducts. Together with classical concrete solutions, new steel–concrete composite typologies have been developed, giving light and cheap structures. Despite these studies and applications, some concerns still remain about the definition of reliable models for the evaluation of their actual dynamical behaviour under HS train passage. In particular, the influence of many structural and non-structural components, such as cross-girders and ballast, are still not well recognised. In this paper, open problems related to the dynamical assessment and modelling of new steel–concrete four-parallel-girder and box-girder solutions are exposed and analysed. A suitable procedure, based on operational modal analysis, model updating and train–bridge interaction analysis is applied to two bridges, recently built in the new Italian HS network, in order to assess and verify their dynamic behaviour under operative conditions.

Numerical analysis on seismic response of Shinkansen bridge-train interaction system under moderate earthquakes

This study is intended to evaluate the influence of dynamic bridge-train interaction (BTI) on the seismic response of the Shinkansen system in Japan under moderate earthquakes. An analytical approach to simulate the seismic response of the BTI system is developed. In this approach, the behavior of the bridge structure is assumed to be within the elastic range under moderate ground motions. A bullet train car model idealized as a sprung-mass system is established. The viaduct is modeled with 3D finite elements. The BTI analysis algorithm is verified by comparing the analytical and experimental results. The seismic analysis is validated through comparison with a general program. Then, the seismic responses of the BTI system are simulated and evaluated. Some useful conclusions are drawn, indicating the importance of a proper consideration of the dynamic BTI in seismic design.

A Bridge Damage Detection Approach using Train-Bridge Interaction Analysis and GA Optimization

This research is intended to establish a bridge damage detection approach employing only direct analyses of traininduced vibration by means of introducing soft computing methods. In this approach, different from identifying the structural damages using inverse analyses, the possible damage patterns of the bridge are assumed at first. Then, the running train-induced bridge vibration under a certain damage pattern is calculated employing a developed trainbridge interaction analysis procedure. When the calculated response is identical to the recorded one, this damage pattern will be the solution. However, owing to the large number of damage patterns, it is difficult to identify the exact solution. Therefore in this approach, the optimization method of Genetic Algorithm is applied to identify the damage pattern including the damage locations and degrees, in which the difference between the calculated results and the recorded responses is defined as the object function. The basic models and process of this approach are introduced in this paper.

Dynamic analysis of a train-bridge system under multi-support seismic excitations

A numerical solution for the dynamic responses of a train-bridge interaction system subjected to multi-support seismic loads was studied. The train vehicle was modeled by the rigid-body dynamics method, and the bridge was modeled by the finite element method. The vertical and lateral wheel-rail interaction forces were defined according to the wheel-rail corresponding assumption and the simplified Kalker creep theory. Three-dimensional seismic accelerations were incorporated using the large mass method. In a case study, the dynamic responses were simulated for a high-speed train traversing a steel truss cable-stayed bridge with different seismic intensities and different train speeds, and train safety was evaluated.

Structural analysis of 3D high-speed train–bridge interactions for simple train load models

Three-dimensional models are developed for analysing the dynamic interaction that occurs between high-speed trains and bridges. The reliability and accuracy of developed models are verified by comparing the results from analysing field tests on high-speed trains. A number of train load models are proposed and their performances are compared in order to identify possible models that would reduce the computational and modelling efforts while maintaining suitable accuracy. The results show that at least 16 cars out of a 20-car train should be modelled to achieve results that are comparable to those obtained using the highly detailed 20-car model. Regarding the simplified train load model, more accurate results are obtained employing the 3D moving vehicle model for power cars, the heaviest cars of a high-speed trainset, and a moving force model for other cars, power passenger cars, and passenger cars, compared with highly detailed 20-car model.