Jamming in 2-D Prolate Granular Material Systems.

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Jamming in 2-D Prolate Granular Material Systems.
Jesus Benhumea Kevin Stokely Matt
Aggleton Advisor Dr. Scott Franklin
Petroleum Research Fund 39132-GB9
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Outline

• Background
• Experimental Setup
• Video
• Data Analysis
• Data
• Conclusion

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Background

• Prolate particles are characterized by large
  aspect ratio (? L/W gt 10)
• Piles are much more rigid than ordinary granular
  materials
• Jamming To cause (moving parts, for example) to
  lock into an unworkable position
• Oil industry
• Farming
• Manufacturers of items such as Nails, pens, etc..
• Timber Industry
• Anywhere prolate granular materials are found
• What Triggers Jamming to occur more frequently?

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Experimental Setup

• 2-D flat surface
• Dimensions 12x20
• Square Brass Rods 2.5 X .125 ? 20
• Packing fraction Area of rods/ Total Area

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• A .5 probe is driven through the pile.

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Angular Distribution

• The rods are laid and spread out by hand
• An initial image is taken and analyzed to ensure
  randomness and isotropy

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What Are we are Looking for

• Total number of Particles that are disturbed in a
  run?
• How far ahead, above, and below does the
  disturbance reach?
• How many particles are pushed off the plate?
• What force is felt by the probe from the
  particles?

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Video Data
? 40
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Video Data
? 13
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Video Analysis

• We Subtract Images to determine which rods have
  moved.
• Bright Spots Indicate Disturbance

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Subtracted Video
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• More particles lead to more moving in disturbance

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• Motion of Particles ahead of the Dot

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• Motion of particles above and below the dot.

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• Rods pushed off of the plate.

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Conclusion

• Jamming and more body like movements occur around
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• Future Plans
• We plan to include a force sensor to measure the
  forces that occur
• Track the movement of one or more particles with
  fluorescent paint.
• Make the transition to multi-level piles