Project Rampway

ME 450–Finite Element Analysis Spring 07Aaron Emmons, Bryce Young and Eric BushProfessor Dr. K. NemaMonday – April 30th, 2007

Presentation SummaryEric• Objective• Introduction • Theoretical Concepts• Model Details / Material Properties / Cost

Aaron• Loading Cases• Results and Discussion

Bryce• Finish Results and Discussion• Impact Statement• Present Conclusions

Objectives

• Utilize knowledge learned through Mechanical Engineering to obtain experimental results on a real-world example

• Examine two different materials to optimize a motorcycle ramp for structural integrity and usability

• Accomplished by structural Finite Element Analysis of both aluminum and steel ramps through Pro/E and Pro/E Mechanica

Introduction

Project Background / Goal 1. To produce the groundwork for material selection and

load limits for a motorcycle loading ramp. (pickup truck)

– Use Finite Element Analysis to understand performance of aluminum and steel

– Compare Weight and Cost

Previous Work1. Finite Element Analysis of experimental objects in ME

450

Theoretical Background

Von Mises Stress in 3 dimensions:

Displacement in terms of Cartesian components:

Theoretical Background Cont.

Relation between Von Mises, Yield Strength, and factor of safety:

Factor of Safety:

safetyoffactorStressMaximum

MaterialofStressYield__

_

___

Model Details

• Table 1: Ramp Dimensions

Ramp Dimensions

Dimension metric SI

Length 2.2350m 7.33ft

Width 0.3048m 1.00ft

Top Surface Area 0.3786m^2 4.075ft^2

Volume 0.009m^3 0.318ft^3

Model Details II

• Table 2: Material Properties

Material Properties (3)

property Steel Aluminum unit

E 200 72.4 Gpa

p 7861.1 2795 kg/m^3

poison ratio 0.29 0.33  

yield strength 434 414 Mpa

ultimate yield strength 703 469 Mpa

Model Details III

• Table 3: Steel vs. Aluminum Properties

MaterialWeight

(kg)Weight

(lb)Cost ($/lb)

Raw Material Cost ($)

Aluminum 25.06 55.21 17.50 966.15

Steel 70.48 155.28 7.77 1206.51

Model Details IV

Mesh

• Automatically generated by Pro-Mechanica at 1300 elements

• Multi-pass adaptive solution

Model Loading

• Uniform Pressure Load, Central Localized Load and Off-centered Localized Load

• Ramp is fixed for zero displacement at the base as well as the top angled flange to simulate ground and truck bed loading conditions

Loading Conditions

• Uniform Pressure Load – used to establish initial maximum load and force per unit area

• Central Localized Load – set at approximately 60 inches (average wheel base of motorcycle) to simulate motorcycle tires

• Off-Center Localized Load – real world condition of loading motorcycle up ramp under the assumption tires will not follow center of ramp

Results and Discussion

• Von Mises Stress and Displacement Analysis for Aluminum vs. Steel

1. Uniform Pressure Load

2. Central Localized Load

3. Off-center Localized Load

Uniform Pressure LoadAluminum

• Von Mises Stress Analysis (Load = 16000 N/m^2)

Uniform Pressure LoadSteel

• Von Mises Stress Analysis (Load = 17500 N/m^2)

Uniform Pressure Load Aluminum

• Displacement (Load = 16000 N/m^2)

Uniform Pressure LoadSteel

• Displacement (Load = 17500 N/m^2)

Results of Uniform Pressure Load

Aluminum

Steel

N Load (N/m^2)

Max Max Yield Factor

Displacement (m) Stress Stress (MPa) of Safety

  (MPa)    

5512 16000 0.03703 413 414 1

N Load (N/m^2)

Max Max Yield Factor

Displacement (m) Stress Stress (MPa) of Safety

  (MPa)    

6029 17500 0.0148 433.5 434 1

Central Localized Load• Von Mises Stress Analysis (Load = 4479 N)

Aluminum Steel

Central Localized Load• Displacement (Load = 4479 N)

Aluminum Steel

Results of Central Localized Load

Aluminum

Steel

N Load (N/m^2)

Max Max Yield Factor

Displacement (m) Stress Stress (MPa) of Safety

  (MPa)    

4479 13000 0.00966 129.3 414 3.2

N Load (N/m^2)

Max Max Yield Factor

Displacement (m) Stress Stress (MPa) of Safety

  (MPa)    

4479 13000 0.003515 130.4 434 3.33

Off-Center Localized Load• Von Mises Stress Analysis (Load = 4479 N)

Aluminum Steel

Off-Center Localized Load• Displacement (Load = 4479 N)

Aluminum Steel

Off-Center Localized Load

• Bending due to off-center loading

Results of Off-Center Localized Load

Aluminum

Steel

N Load (N/m^2)

Max Max Yield Factor

Displacement (m) Stress Stress (MPa) of Safety

  (MPa)    

4479 13000 0.00995 141.3 414 2.93

N Load (N/m^2)

Max Max Yield Factor

Displacement (m) Stress Stress (MPa) of Safety

  (MPa)    

4479 13000 0.00362 142.2 434 3.05

Impact Statement

• This project is simulates a material selection and design validation process that a manufacturer would use in choosing a material and verifying the functional limits of a design prior to production.

• An FEA analysis aids in producing a product that performs as advertised, which allows the production a safe and cost effective design that fulfills the needs of consumers.

• Due to familiarity, Pro/E Mechanica was used to as the FEA software to perform the described analysis.

Conclusions

• The highest magnitude of stress occurred at the intersection of the angled flange

• The largest displacements occurred at the center of the ramp.

• Cost - Aluminum cost less than steel by more than $240

• Weight – Steel out weighs aluminum by more than 100 lbs increasing the difficulties associated with normal use and transportation

Conclusions Cont.

• Strength – For the same design, steel’s structural properties are superior to aluminums allowing for higher load limits and smaller displacements under the load conditions produce by a 1000lb motorcycle.

• Consider weight, cost, and loaded performance, aluminum proved to be the superior material for the motorcycle ramp.

• Aluminum motorcycle ramps are widely produced, indicating that manufacturers arrived at similar conclusions.

References

1. http://www.realclassic.co.uk/ridesfiles/rides05011401.jpg

2. http://www.horizonsunlimited.com/newsletter/images2003/2003-04-01_Maarten-TwoWheeler.jpg

3. ME450 – Lecture Notes via Oncourse

Questions???