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1. Introduction

2. Literature review

3. Wheel force represented as time varying nodal forces

4. Sprung mass represented by time varying stiffnessmatrices

5. Unsprung mass represented by time varying mass,damping, and stiffness matrices within a modal and

finite element framework6. Wheel rail systems on irregularities

7. Conclusions & recommendations

8. Appendices

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ANSYS Strengths Element Library

Equation Solvers

Post-processor tool

APDL Code

ANSYS Limitations No force between nodes

Contact elements cant model

irregularities or braking forces

3D contacts need surface

Dynamic effects of trains traversing railway bridges

Centre span of Boyne Viaduct Railway bridgeCentre span of Boyne Viaduct Railway bridge

Modelled using ANSYS finite element program

Development own models

Wheels modelled as moving forces

Wheels modelled as sprung masses

Wheels modelled as unsprung mass (modal & finite element)

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Moti tions Moving Force odel s it le for long s n ridges

Ti e of exec tionof odel re gener ll ver s ort

ANSYS c nnot l force et eennodes of single ele ent Developments

Simple andExact numericalmodels for single moving force

Expandmodels for several moving forces

es lts alidated singnumericalmodels from t e literature

Simulate Dand D oyne ridge to several moving forces

esonance canoccur due to closely spacedve icle loadings

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Motivations ANSYS contact elements are unable tomodel irregularities

Develop elements t at canmodel smoot rail and irregularities

Developments ertical springunder eel i.e. Hertzian spring

ongitudinal spring element capture braking effects

ateral spring elements stabilize Dmodels

esults alidatemodel results it results from t e literature as ell asANSYS contact elements

Train eels as sprungmasses traversing oyne iaduct

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Motivations Toaddress t e issue of omitting convective acceleration

T e ability to compare it sprungmass models

Developments Modalmet od for movingunsprungmass

Finite element model for movingunsprungmass

Expand to simulate several movingunsprungmasses

esults alidatemodel results it results from t e literature

AddressingAkin Mofids incorrectmodel results

Sensitivityof internal forces

Train eels as unsprungmasses traversing oyne iaduct

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Motivations Simulate realistic eel-rail conditions

ANSYS contact elements cannot model irregularities

Developments Modify sprungmass model to simulate rail irregularities

Modifyunsprungmassmodels to simulate rail irregularities

esults

alidatemodel results it results from t e literature Train traversing oyne iaduct it irregularities along rails

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ANSYS limitation for modelling moving forces

Simple or Exact numerical models can now be used

ANSYS contacts cannot model irregularities

Development of WRC element WRC element more accurate than ANSYS contact elements

WRC element can model rail irregularities, braking, lateral

stability, wheel separation as well as rigid rails

Developed unsprung models Address the issue of Akin & Mofids results been inaccurate

Comparable with sprung mass model (under certain circumstances)

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Contains many fundamental equations used throughout

the thesis as well as bridge and train properties

Areas of interested include:

Convention Elastic beam theory

inite element method applied to equation of motion of a beam

Natural frequencies and modal shapes for a beam

Beam Damping

Newmark time integration scheme

Bridge dimensions, material and section properties

Railway vehicle dynamics