BIKE BRAKE LEVER DESING Continuum Mechanics Members of the group: - - PowerPoint PPT Presentation

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BIKE BRAKE LEVER DESING Continuum Mechanics Members of the group: - - PowerPoint PPT Presentation

Jun 04, 2023 778 likes •1.18k views

BIKE BRAKE LEVER DESING Continuum Mechanics Members of the group: Fargas Cabanillas, Josep Maria Oliv Delgado, Roger Sansalvad Cabons, Clara 1 1) FIRSTS STEPS-INTRODUCTION BIKE BRAKE LEVER DESING -Continuum Mechanics 2

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BIKE BRAKE LEVER DESING Continuum Mechanics

Members of the group:

Fargas Cabanillas, Josep Maria Olivé Delgado, Roger Sansalvadó Cabonés, Clara 1

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BIKE BRAKE LEVER DESING-Continuum Mechanics

1) FIRSTS STEPS-INTRODUCTION

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BIKE BRAKE LEVER DESING-Continuum Mechanics

INTRODUCTION: Basic function and key points

 Aim: Design a brake lever  Use: The basic function of brake levers is to activate the brake mechanism  They have not only hardness and stiffness but also lightness and resistance  Legislation:

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BIKE BRAKE LEVER DESING-Continuum Mechanics

1) FIRSTS STEPS-MATERIAL SELECTION

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BIKE BRAKE LEVER DESING-Continuum Mechanics

MATERIAL SELECTION

Aluminium 6082

Plate thick: 6mm Laser cutting

Density Modulus of Elasticity Poisson coefficient Yield point Melting point Break load 2,7 g/cm3 70 GPa 0.33 260 MPa 555ºC 310 MPa

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BIKE BRAKE LEVER DESING-Continuum Mechanics

1) FIRSTS STEPS-PRELIMINARY DESING

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BIKE BRAKE LEVER DESING-Continuum Mechanics

PRELIMINARY DESING: Data

Pressure P Force (Fmax) Thickness (t) Width (L)  Research  Our own experiments Data values Real project Academical project 7

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BIKE BRAKE LEVER DESING-Continuum Mechanics

PRELIMINARY DESING: Maximum permisible force

 This graph comes from joining three ergonomic studies

 Real brake lever design: statistical data Our project: Our own experiments, team members data

Fmax = 535,7 N Fmax = 392 N 8

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BIKE BRAKE LEVER DESING-Continuum Mechanics

PRELIMINARY DESING: Hand width

 Real brake lever design: statistical data Our project: Our own experiments, team members data

L = 57,25 mm L = 70 mm 9

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BIKE BRAKE LEVER DESING-Continuum Mechanics

PRELIMINARY DESING: Data

Pressure P Force (Fmax) = 40*9,8 = 392 N Thickness (t) = 6mm Width (L) = 70mm  Research  Our own experiments Data values Real project 10

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BIKE BRAKE LEVER DESING-Continuum Mechanics

PRELIMINARY DESING

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BIKE BRAKE LEVER DESING-Continuum Mechanics

2) FINITE ELEMENTS MODEL-Boundary conditions

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINITE ELEMENTS METHOD: Boundary conditions

Equations A: P1-T=0 B: P2-F=0 C : T*X-F*L=0 Hypothesis:

  • 1. Static model
  • 2. Pressure (Pr): Uniform and

perpendicular to the surface

  • 3. Punctual contact produces

punctual forces at M, N, O. M N O Pr 13

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BIKE BRAKE LEVER DESING-Continuum Mechanics

2) FINITE ELEMENTS MODEL-Model characteristics

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINITE ELEMENTS METHOD: Model characteristics We choose 183 element type:

  • Quadratic interpolation thus

more precision (curved edges).

  • We are not restricted for

computational power  Plane tension analysis

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 Material properties: Linear, elastic, isotropic E= 70 GPa v= 0,33

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BIKE BRAKE LEVER DESING-Continuum Mechanics

2) FINITE ELEMENTS MODEL-Results reliability

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINITE ELEMENTS METHOD: Results reliability

 Are numeric singularities affecting our results?  Do we need non-linear study? Linear: R= 865,95 N Non-linear: R= 860,89 N

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINITE ELEMENTS METHOD: Results friability

 Refining mesh Biggest element size with stable results

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BIKE BRAKE LEVER DESING-Continuum Mechanics

3) RESULTS ANALYSIS-Current displacements

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BIKE BRAKE LEVER DESING-Continuum Mechanics

RESULTS ANALYSIS: current displacements

Maximum displacement: 1,94mm Small maximum strain: 3,3·10-3

Displacement Deformed shape Total strain

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BIKE BRAKE LEVER DESING-Continuum Mechanics

3) RESULTS ANALYSIS-principal strength distribution and directions

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BIKE BRAKE LEVER DESING-Continuum Mechanics

RESULTS ANALYSIS: principal strength distribution

1st principal direction 2nd principal direction 3rd principal direction Principal stress distribution

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BIKE BRAKE LEVER DESING-Continuum Mechanics

3) RESULTS ANALYSIS-Failure criteria

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BIKE BRAKE LEVER DESING-Continuum Mechanics

RESULTS ANALYSIS: Failure criteria

Posible failure criteria:  Tresca-Guest

  • Von Mises

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BIKE BRAKE LEVER DESING-Continuum Mechanics

3) RESULTS ANALYSIS-Security coefficient

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BIKE BRAKE LEVER DESING-Continuum Mechanics

RESULTS ANALYSIS: Security coefficient

3 , 1 2 , 1   

eq e

s  

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 Our brake lever σe = 260 MPa σeq= 172,73 Mpa

𝛿 = 1,505

Pe = 1,4 MPa Peq= 0,93 Mpa

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BIKE BRAKE LEVER DESING-Continuum Mechanics

4) FINAL DESING- Optimization

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINAL DESING- Optimization

Problem! 28

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINAL DESING- Optimization

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FINAL DESING- Optimization

 Prototypes and final design

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BIKE BRAKE LEVER DESING-Continuum Mechanics

4) FINAL DESING- Summary

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BIKE BRAKE LEVER DESING-Continuum Mechanics

Boundary conditions

FINAL DESING-Summary

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Pressure: Pn = 0,93 MPa Force: Fmax = 392N Thickness: t = 6mm Width: L = 70mm

3 , 1 2 , 1   

eq e

s  

σe = 260 MPa σeq= 214,8 Mpa

𝛿 = 1,21

Pe = 1,13 MPa Peq= 0,93 Mpa

Security coefficient

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FINAL DESING-Summary

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Nonlinear deformed shape Linear deformed shape Mesh refining

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4) FINAL DESING-Environmental impact. Construction and cost.

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINAL DESING- Environmental impact. Construction and cost

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 Environmental impact

  • A. Our brake lever

 Construction and cost

Aluminium: 100% recyclable. Recicled aluminium: 5% of the energy needed to obtain aluminium from the bauxite minerale. Laser cutting Gluing Aluminium plate Separated shapes Brake lever

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINAL DESING- Environmental impact. Construction and cost

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  • B. Mass production

 Economical (for big series)  Sustainable Laser cutting: 14,44€/u x 2u 28,88€ Gluing the shapes: + 5€ Total 33,88€

  • 1. Design

extrusion die

  • 3. Cut slices
  • 4. Somoothen

the brake lever

  • 2. Extrude

profile

Cost

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BIKE BRAKE LEVER DESING-Continuum Mechanics

4) FINAL DESING-Test

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINAL DESING-Test

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Validating the simulation:

 Analytically  Test

R

76,37 mm 34,57 mm 20,24 mm 49,63 mm 30 mm

F 1 F 2 R=(34,57F 1+76,37F 2)/30

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BIKE BRAKE LEVER DESING-Continuum Mechanics

FINITE ELEMENTS METHOD: Possible improvements

Questions?

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