ENAC Semester Project Final Presentation Presenter Qimin Wang - - PowerPoint PPT Presentation

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ENAC Semester Project Final Presentation Presenter Qimin Wang - - PowerPoint PPT Presentation

ENAC Semester Project Final Presentation Presenter Qimin Wang Supervisor Prof. Molinari Jean-Franois Dr. Nicolas Richard Dr. Roozbeh Rezakhani Mrdalsjkull Glacier, Iceland Photo by Qimin Wang CONTENTS INTRODUCTION


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ENAC Semester Project Final Presentation

Presenter Qimin Wang Supervisor

  • Prof. Molinari Jean-François
  • Dr. Nicolas Richard
  • Dr. Roozbeh Rezakhani
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Mýrdalsjökull Glacier, Iceland Photo by Qimin Wang

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ENAC Semester Project Final Presentation

CONTENTS

INTRODUCTION PREVIOUS WORK UPDATED RESULTS CONCLUSIONS

Ⅰ Ⅱ Ⅲ Ⅳ

ENAC Semester Project Mid-term presentation

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ENAC Semester Project Final Presentation

Ⅰ INTRODUCTION

Date Source Background

Ø Data of the Bowdoin glacier calving in 2017 from Eef Van Dongen, ETH Zurich Ø Ice calving

“the breaking of ice chunks from the edge of a glacier”

——Essentials of Geology, 3rd edition

Project Goal

Ø Viscous behavior on long time scale Ø Elastic behavior on short time scale

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ENAC Semester Project Final Presentation

Ⅰ INTRODUCTION

Picture from Eef Van Dongen Bowdoin Glacier Calving in July 2017

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ENAC Semester Project Final Presentation

Ⅰ INTRODUCTION

Ø Cause of Ice calving: 1st , 2nd , and 3rd order processes Longitudinal stretching is the 1st order process.

longitudinal stretching friction glacier geometry water pressure

Iceberg Sea Base

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Ⅰ INTRODUCTION Break-off + rotation if width < thickness

Tabular icebergs if width > thickness

Calving events resulting from various geometries Picture from Dr. Eef

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Ⅰ INTRODUCTION Water-free crevasses trigger small calving Water-filled crevasses trigger large calving

Calving events resulting from different water conditions Picture from Dr. Eef

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ENAC Semester Project Final Presentation

Data Structure

Ⅱ INTRODUCTION

Data Meshfiles radarVelocity satVelocity tides fracture

From 4/7/2017 to 8/7/2017

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Ⅱ DATA & SIMULATION

Ø Meshfiles of different resolutions

10 m 20 m 10 m with crack

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Ø Mesh for currency study

Resolution: 20m Nodes: 53,523

Ⅱ DATA & SIMULATION

top bottom side2: waterfront side4 side1 side3 An enormous chocolate bar! 3.23 km in length 1.04 km in width 352 m in height

3:1:0.3

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ENAC Semester Project Final Presentation

Ⅱ DATA & SIMULATION

Ø radarVelocity/ satVelocity

Velocity at the top surface: derived from rader interferometry Body velocity: solved by the Navier-Stokes equations excluding acceleration

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ENAC Semester Project Final Presentation

CONTENTS

INTRODUCTION PREVIOUS WORK UPDATED RESULTS FUTURE PLAN

ENAC Semester Project Mid-term presentation

The

Ⅰ Ⅱ Ⅲ Ⅳ

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Ø Boundary conditions Ø Initial Conditions Body velocity

Ⅲ UPDATED RESULT

Water pressure Surface velocity

g

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  • Understood the provided data
  • Learned how to use Akantu and Fidis
  • Coded for basic explicit simulation

Ⅳ PREVIOUS WORK

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ØFuture work

  • Review our goals
  • Viscous behavior on long time scale
  • Elastic behavior on short time scale
  • Tides impact (i.e., how to apply time-dependent

boundary condition)

  • Crack and the water pressure behind
  • Glacier elevation
  • Implicit integration methods

Ⅳ PREVIOUS WORK

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Ø tides

4 July 8 July

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CONTENTS

INTRODUCTION PREVIOUS WORK UPDATED RESULTS CONCLUSION

Ⅰ Ⅱ Ⅲ Ⅳ

The

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  • Tested and optimized parallel computing setup
  • Coded for time-dependent B.C.
  • Coded for mesh coordinates translation
  • Studied the impact of how to apply B.C.s
  • Redefined the simulation steps
  • Considered the material damage

Ⅲ UPDATED RESULT

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Ⅲ UPDATED RESULT

ØDistributed mesh for HPC

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  • Impact of how to apply B.C.s

Ⅲ UPDATED RESULT

10#𝑂 10%&𝑛/𝑡

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3s 10s 30s

Ø Loading profiles for the water pressure

Factor of water pressure Time/s

Ⅲ UPDATED RESULT

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Ø Kinetic Energy Variation

These loading profiles do not change the maximum

  • f the kinetic energy

Ⅲ UPDATED RESULT

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Ø Comparison of Kinetic Energy and Potential Energy

log 𝐹0 𝐹1 ≈ log 1034 1045 = 7

Ⅲ UPDATED RESULT

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Ⅲ UPDATED RESULT

Ø Propagation of stress wave

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Ⅲ UPDATED RESULT

Ø Modified simulation scheme

  • 1. Static step: balanced water pressure with deformation
  • 2. Explicit step: long-term effect of velocity
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Ø Material damage Mazars model: A behavioral model to represent damage evolution in concrete. The damage is directly evaluated from the strain

Ⅱ DATA & SIMULATION

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Ø System Energy Variation

Ⅲ UPDATED RESULT

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Ⅲ UPDATED RESULT t = 55 s t = 65 s t = 75s

Ø Damage propagation Causes:

  • Fixed B.C.
  • Coarse mesh
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ENAC Semester Project Final Presentation

CONTENTS

INTRODUCTION PREVIOUS WORK UPDATED RESULTS CONCLUSION

Ⅰ Ⅱ Ⅲ Ⅳ

ENAC Semester Project Mid-term presentation

The

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What have been done?

  • The basic workflow using Akantu for HPC
  • Relationship between loadings and system energy
  • Simulation scheme and simulation acceleration
  • Damage initiation and propagation

Ⅳ CONCLUSION

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Future work:

  • Redesign the simulation scheme and B.C.s
  • Test the proper material damage models
  • Use weaker material around the crack propagation region
  • Simulate with finer mesh

Ⅳ CONCLUSION

Crack detail in the finer mesh.

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Thank you for your attention!