This document describes a structural analysis of a road bridge using finite element modeling. It provides background on bridges and their types. The analysis procedure involves creating a 3D model of the bridge in ANSYS, defining the material properties of steel and concrete, meshing the model into finite elements, and applying boundary conditions to model how the bridge is supported. The results will provide insights into the stresses and performance of the bridge structure.

1. A
PROJECT BASED LAB REPORT
On
STRUCTURAL ANALYSIS OF A ROAD BRIDGE
In the course of finite element method
Submitted in partial fulfilment of the
Requirements for the award of the Degree of
Bachelor of Technology
In
MechanicalEngineering
By
Subham kumar gupta
(14007582)
DEPARTMENT OF MECHANICAL ENGINEERING
(DST-FIST Sponsored Department)
K L University
Green Fields, Vaddeswaram, Guntur District-522 502
2016-2017
K L University
DEPARTMENT OF MECHANICAL ENGINEERING

2. This is to certify that this project based lab report entitled “STRUCTURAL ANALYSIS OF ROAD
BRIDGE” is a bonafide work done by subham kumar gupta (14007582), in partial fulfillment
of the requirement for the award of degree in BACHELOR OF TECHNOLOGY in
Mechanical engineering during the Acadamic year 2016.
Lecturer In Charge Head of the Department
Mr.anna eswar Dr.S S RAO
CERTIFICATE

3. K L University
DEPARTMENT OF MECHANICAL ENGINEERING
We hereby declare that this project based lab report entitled “Structural analysis of a road bridge”
hasbeen preparedby us in partial fulfilment of the requirement for the awardof degree “BACHELOR
OF TECHNOLOGYin MECHANICAL ENGINEERING” during the academic year 2016-2017.
I also declare that this project based lab report is of our own effort and it has not been
submitted to any other university for the award of any degree.
Date: Name
Place:Vadeswaram SUBHAM KUMAR GUPTA (14007582),
DECLARATION

4. ACKNOWLEDGEMENTS
My sincere thanks MR. ANNA ESWAR Sir in the Lab for their outstanding support
throughout the project for the successful completion of the work
We express our gratitude to Dr.S S RAO, Head of the Department for Mechanical
Engineering for providing us with adequate facilities, ways and means by which we are
able to complete this project work.
We would like to place on record the deep sense of gratitude to the honourable Vice
Chancellor, K L University for providing the necessary facilities to carry the concluded
project work.
Last but not the least, we thank all Teaching and Non-Teaching Staff of our department and
especially my friends for their support in the completion of our project work.
Name
Subhamkumar gupta(14007582)

5. CONTENTS
1. ABSTRACT
2. INTRODUCTION
3. BRIDGES & ITS TYPES
4. STRUCTURALANALYSIS
5. PROCEDURE FOR ANALYSIS
6. RESULTS
7. BIBLIOGRAPHY
ABSTRACT
This thesis addresses key issue related to the analysis of failure in bridges.In order to
perform analysis procedure,an in depth understanding of the stresses,strain,strain energy
involved in the failure as the peak load is key to a successful.
Bridges like road bridges,rail bridges are need to be analyse first before making it. In this
project we are going to make structural analysis of “KUNCHANPALLI BRIDGE” and load test
results in association with finite element method model.
Load
Bridge

6. 6
INTRODUCTION:
A bridge isa structure builttospan physical obstacleswithoutclosingthe wayunderneathsuchasa
bodyof water,valley,orroad,forthe purpose of providingpassage overthe obstacle.There are
manydifferentdesignsthateachserve aparticularpurpose andapplyto differentsituations.
Designsof bridgesvarydependingonthe functionof the bridge,the nature of the terrainwhere the
bridge isconstructedandanchored,the material usedtomake it,and the fundsavailable tobuildit.
Types of bridges
Bridgescan be categorizedinseveral differentways.Commoncategoriesinclude the type of
structural elements used,bywhattheycarry,whethertheyare fixedormovable,andbythe
materialsused.
Structure type:Bridgesmaybe classifiedbyhow the forcesof tension,compression,bending,torsion
and shearare distributedthroughtheirstructure.Mostbridgeswill employall of the principal forces
to some degree,butonlyafewwill predominate.The separationof forcesmaybe quite clear.Ina
suspensionorcable-stayedspan,the elementsintensionare distinctinshape andplacement.In
othercasesthe forces maybe distributedamongalarge numberof members,asina truss,or not
clearlydiscernible toacasual observerasin a box beam.
1.Beam bridge: Beambridgesare horizontal beamssupportedateachendbysubstructure unitsand
can be eithersimplysupportedwhenthe beamsonlyconnectacrossa single span,orcontinuous
whenthe beamsare connectedacrosstwo or more spans.Whenthere are multiplespans,the
intermediate supportsare knownaspiers.The earliestbeambridgeswere simple logsthatsat
across streamsand similarsimple structures.Inmoderntimes,beambridgescanrange fromsmall,
woodenbeamstolarge,steel boxes.The vertical force onthe bridge becomesashearandflexural
loadon the beamwhichistransferreddownitslengthtothe substructuresoneitherside.Theyare
typicallymade of steel,concrete orwood.Beambridge spansrarelyexceed250feet(76 m) long,as
the flexural stressesincreaseproportional tothe square of the length(anddeflectionincreases
proportional tothe 4th powerof the length).However,the mainspanof the Rio-Niteroi Bridge,a
box girderbridge,is300 metres(980 ft).
The world'slongestbeambridge isLake PontchartrainCausewayinsouthernLouisianainthe United
States,at 23.83 miles(38.35 km),withindividual spansof 56 feet(17 m).Beambridgesare the most
commonbridge type inuse today.
2.Truss bridge: A trussbridge isa bridge whose load-bearingsuperstructure iscomposedof atruss.
Thistruss isa structure of connectedelementsforming triangularunits.The connectedelements
(typicallystraight)maybe stressedfromtension,compression,orsometimesbothinresponse to
dynamicloads.Trussbridgesare one of the oldesttypesof modernbridges.The basictypesof truss
bridgesshownin thisarticle have simpledesignswhichcouldbe easilyanalyzedbynineteenthand
earlytwentiethcenturyengineers.A trussbridge iseconomical toconstructowingtoitsefficientuse
of materials.
3.Cantileverbridge:Cantileverbridgesare builtusing cantilevers—horizontal beamssupportedon
onlyone end.Most cantileverbridgesuse apairof continuousspansthatextendfromopposite

7. 7
sidesof the supportingpierstomeetatthe centerof the obstacle the bridge crosses.Cantilever
bridgesare constructedusingmuchthe same materials& techniquesasbeambridges.The
difference comesinthe actionof the forcesthroughthe bridge.
Some cantileverbridgesalsohave asmallerbeamconnectingthe twocantilevers,forextra
strength.The largestcantileverbridge isthe 549-metre (1,801 ft) QuebecBridge inQuebec,Canada.
4.Arch bridge:Arch bridgeshave abutmentsateachend.The weightof the bridge isthrustintothe
abutmentsateitherside.The earliestknownarchbridgeswere builtbythe Greeks,andinclude the
ArkadikoBridge.
Withthe spanof 220 metres(720 ft),the SolkanBridge overthe SočaRiverat SolkaninSloveniais
the secondlargeststone bridge inthe worldandthe longestrailroadstone bridge.Itwascompleted
in1905. Its arch, whichwasconstructedfromover5,000 tonnes(4,900 longtons;5,500 shorttons)
of stone blocksinjust18 days,isthe secondlargeststone archinthe world,surpassedonlybythe
Friedensbrücke (Syratalviadukt) inPlauen,andthe largestrailroadstone arch.The arch of the
Friedensbrücke,whichwasbuiltinthe same year,hasthe span of 90 m (295 ft) and crossesthe
valleyof the SyrabachRiver.The difference betweenthe twoisthatthe SolkanBridge wasbuiltfrom
stone blocks,whereasthe Friedensbrückewasbuiltfromamixture of crushedstone andcement
mortar.The world'scurrentlargestarch bridge isthe ChaotianmenBridge overthe Yangtze River
witha lengthof 1,741 m (5,712 ft) and a span of 552 m (1,811 ft).The bridge wasopenedApril 29,
2009 inChongqing,China.
5.Suspensionbridge:Suspensionbridgesare suspendedfromcables.The earliestsuspensionbridges
were made of ropesor vinescoveredwithpiecesof bamboo.Inmodernbridges,the cableshang
fromtowersthat are attachedto caissons orcofferdams.The caissonsorcofferdamsare implanted
deepintothe floorof a lake or river.Sub-typesinclude the simplesuspensionbridge,the stressed
ribbonbridge,the underspannedsuspensionbridge,the suspended-decksuspensionbridge,andthe
self-anchoredsuspensionbridge.There isalsowhatissometimescalleda"semi-suspension"bridge,
of whichthe FerryBridge inBurton-upon-Trentisthe onlyone of itskindinEurope.[16] Thisisa
three-spanfootbridge totalling240 feetinlength,the suspensionconsistingof flatbar-ironriveted
to the maingirders,notanchoredat a distance.Itwasdesignedandconstructedbya local firm,
Thornewill andWarham.
The longestsuspensionbridge inthe worldisthe 3,909 m (12,825 ft) Akashi KaikyōBridge inJapan.

8. 8
PROCEDURE:-
MODEL:
START ANSYS AND IMPORT FILE:
 Open ANSYS: on cmu cluster machines its under math & stats:
 From the file menu select Import>IGES... and select the following options

9. 9
 Locate your IGS file using the browse button. When you find the file it should look something
like this:
 Your screen wll now look like this (notice the axis directions):
MATERIAL PROPERTIES:
 In order for ansys to do a Fine Element Analysis [FEA] we need to specify what kind of
element we want to use. For this 3d solid we will be using a 10 node tetrahedron shaped
element[solid187]. To set this click on Preprocessor>Element Type>Add/Edit/Delete:

10. 10

 Click 'Add' on the next window(Elements Type) and then find 'Tet 10
node' under 'Structural Mass' -> 'Solids':
 click OK and then click Close on the 'Elements Type' window
 Now we must specify what type of material this solid is. The problem specifies the bridge is
to be made ofsteel and concrete. To enter material data click on Preprocessor>Material
Props>Material Models:
Select Structural>Elastic>Isotropic and enter the following numbers into the window that
appears:
EX refers to Young Modulus, which is 2e5 N/mm2 for steel
PRXY refers to poisson ratio, which is .3 for steel
EX refers to Young Modulus, which is 4.1e5 N/mm2 for concrete
PRXY refers to poisson ratio, which is .21 for concrete

11. 11
 click OK, then close the Define Material Model Behavior' window
MESHING:
 To mesh the volume into individual elements, go to Proprocessor>Meshing>MeshTool:
 The MeshTool window will pop-up on the right side of your screen. Select the following
options and click 'Mesh':
 Select the bridge and click ok:
 mesh will look something like this:

BOUNDARY CONDITIONS:
 Now we have to apply the loadings to our meshed volume. This problem has 2 mounted area
and 1 force.
 Before we apply forces you should familiarize yourself with the pan/zoom/rotate tool. You
can find it under PlotCtrls:
 It has the basic engineering views as well as buttons for rotating about each axis, and
buttons for zooming in and zooming out:
 Once you are familiar with this tool, you can continue on to apply forces
 Since the right & left side of the bridge is mounted it will not displace in any direction. To set
this choose Preprocessor>Loads>Define
Loads>Apply>Structural>Displacement>On Areas, select the side face and click OK
on the window that pops-up select All DOF and enter a Displacement of 0...the click OK:

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 To apply the force select Define Loads>Structural>Force/Moment>On Nodes:
 You will apply the forces on the base of the bridge. This will make the loading symmetric
about the center plane of the bridge .
 A window will appear asking for the force data. To have a net force of -600
 N, you will need to apply -600 N to each of the nodes you have chosen. Enter the values
shown below: Notice a downward force is -600 because the positive y direction points up.

 Your bridge should now look like this:

13. 13

SOLVE:
 To run the FEA on the bridge select Solution>Solve>Current LS:
 and your bridge will look like this:

POSTPROCESSING:
 To see the deformed shape of the bridge select General Postproc>Plot
Results>Deformed Shape click OK on the window that appears and the results is:To get
various results for the bridge select General Postproc>Plot Results>Contour
Plot>Nodal Solu:
 To see the stress in the X direction select the following:

14. 14
RESULTS:
 use the 'Pan/Zoom/Rotate' tool to see the 3d stresses. Notice MX and MN locate
maximum and minimum stresses
 or stress in the Y direction:

And deformed +undeformed shaped is shown below

15. 15
CONCLUSION:
• The accuracy of the model wasvalidated,andthe limitationsof matchingfinite elementmodelsto
experimental testsheldunderconditionsthatare lessthanideal wasillustrated.
• The developmentof afinite elementmodelof anentire bridge illustratesnotonlythe capabilityof
bridge torepresentthe behaviorof arealisticstructure butalsothe specificcapabilityof the model
to predictdeflections,strains,andstresseswhileminimizingunnecessarycomplexities.
BIBLIOGRAPHY/REFERENCES:
http://www.wikipedia.com/road/bridges
http://www.hillagric.edu.in/edu/coa/agengg/lecture/243/pipi%2398%road/bridges /
http://www.innovativehub.com/twowheeler/structuralanalysis/