FEA COURSE PROJECTStructural analysis of the cycle frame under static condition

TYRONE MACHADO (BE MECH B 45)

RAHUL PARI (BE MECH B 55)

ACKNOWLEDEMENT

I would like to thank Professor Johnson for his guidance throughoutthe completion of my FEA project. I would also like to thank myColleagues for their support throughout my entire project.I would like to thank the Mechanical Department of DBIT for allowing us to use the college facilities efficiently.

TABLE OF CONTENT

1 Acknowledgemnet

2 List of figures

3 Introduction

4 Analysis

5 Result

6 Conclusion

7 Reference

LIST OF FIGURES

FIG 1-FRONT IMPACT (TOTAL DEFORMATION)

FIG 2-FRONT IMPACT (FOS)

FIG 3-SIDE IMPACT (TOTAL DEFORMATION)

FIG 4-SIDE IMPACT (FOS)

FIG 5-ROLL OVER(TOTAL DEFORMATION)

FIG 6-ROLL OVER (FOS)

IntroductionA bicycle, often called a bike or cycle, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A bicycle rider is called a cyclist, or bicyclist.

FRAMEThe great majority of today's bicycles have a frame with upright seating that looks much like the first chain-driven bike.[3] These upright bicycles almost always feature the diamond frame, a truss consisting of two triangles: the front triangle and the rear triangle. The front triangle consists of the head tube, top tube, down tube, and seat tube. The head tube contains the headset, the set of bearings that allows the fork to turn smoothly for steering and balance. The top tube connects the head tube to the seat tube at the top, and the down tube connects the head tube to the bottom bracket. The rear triangle consists of the seat tube and paired chain stays and seat stays. The chain stays run parallel to the chain, connecting the bottom bracket to the rear dropout, where the axle for the rear wheel is held. The seat stays connect the top of the seat tube (at or near the same point as the top tube) to the rear fork ends

Analysis

Problem Statement

To analyse the Frame of cycle carrying a cyclist.

The FBD of above problem

Ground Level

75 mm

325 mm

500 mm 325 mm

600 N

200 N

Preprocessing: Defining the Problem Defining Some VariablesUsing the 'ANSYS Input' window to input the command line codes for the verification model. Type in each of the following linesfollowed by Enter.x1 = 500x2 = 825y1 = 325y2 = 400z1 = 50

Create LinesUsing the command line to create the lines. The command format to createline L,1,2L,3,2L,3,4L,1,4L,3,5L,4,5L,3.6L,4,6Define the Type of ElementPreprocessor > Element Type > Add/Edit/Delete > AddDefine Geometric PropertiesPreprocessor > Real Constants > Add/Edit/DeleteNow specify geometric properties for the elementsOutside diameter OD: 25Wall thickness TKWALL: 2

Element Material PropertiesTo set Young's Modulus MP,EX,1,70000 To set Poisson's ratio MP,PRXY,1,0.33 Mesh Sizeset the element length to 20 mmPreprocessor > Meshing > Size Cntrls > ManualSize > Lines > All LinesMeshNow the frame can be meshed.In the 'Preprocessor' menu select 'Mesh' > 'Lines' and click 'Pick All' in the 'Mesh Lines' WindowSaveUtility Menu > File > Save as

Solution Phase: Assigning Loads and SolvingClose the 'Preprocessor' menu and open up the 'Solution' menu (from the same 'ANSYS Main Menu').Define Analysis TypeSolution > Analysis Type > New Analysis... > StaticApply ConstraintsDK, KPOI, Lab, VALUE, VALUE2, KEXPND, Lab2, Lab3, Lab4, Lab5, Lab6Displacement on K, K #, DOF label, value, value2, Expansion key, other DOF laNot all of the fields are required for this example, therefore when entering the code certain fields will beempty. For example, to pin the first keypoint enter:DK,1,UX,0,,,UY,UZDK,5,UY,0,,,UZDK,6,UX0,,,UY,,,,UZApply LoadsWe will apply vertical downward loads of 600N at the seat post location at keypoint 3 and 200N at the pedal crank location at keypoint 4

To apply a force of 600N downward at keypoint 3, FK,3,FY,-600 To apply a force of 200N downward at keypoint 3, FK,4,FY,-200

Solving the SystemSolution > Solve > Current LS

Postprocessing: Viewing the ResultsTo begin Postprocessing, open the 'General Postproc' MenuDeformationPlot Results > Deformed Shape... 'Def + undef edge'

DeflectionsThe deflections have been calculated at theUtility menu > PlotCtrls > Numbering... and turn on 'Node numbers'. Turn everything else off.List the Nodal Deflections Main Menu > General Postproc > List Results > Nodal Solution.Plot the deflection General Postproc > Plot Results > (-Contour Plot-) Nodal Solution select 'DOF solution' and 'USUM' in the window

Element ForcesSelect 'Element Solution...' from the 'List Results' menu.Select 'Nodal force data' and 'All forces' from the lists displayed.Click on 'OK'.Stresses General Postproc > Element Table > Define Table ... Select 'Add'Select 'Stress' and 'von Mises'Element Table > Plot Elem Table

Bending Moment Diagrams.Select Element Table > Define Table SMISC,6 SMISC,12Main Menu > General Postproc > List Results > Bending Moment Diagram.

Reference1. University of Alberta ANSYS Tutorials -

www.mece.ualberta.ca/tutorials/ansys/BT/Bike/Bike.html2. en.wikipedia.org/wiki/ Bicycle

3. http://www.intownbicycles.com/how-to/bicycle-terms 4. http://www.bikerumor.com/2010/02/23/bikecad-lets-you-build-a-custom-bike-from-

the-ground-up5. http://ww3.cad.de/foren/ubb/uploads/SFroemer/Exercise2-110400.pdf