Auxetic Materials

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Auxetic Materials
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Whats Poisson Ratio?

• Ratio of axial and lateral strains
• Formulated so most materials with positive value
• ? -?x -?y
• ?z ?z

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What are auxetic materials and their properties?

• Materials with a negative Poisson Value
• Density may vary from one-trillionth the density
  of air or 100 billion times air
• Formed -460F or 10,000 heat of white dwarf stars

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Auxetic v. Normal materials

• Auxetic materials
• Larger when stretched
• Smaller when compressed

• Normal materials
• Smaller when stretched
• Larger when compressed

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Applications of Auxetic materials

• Nature
• Neutron stars
• White dwarf
• Skin of a cat

• Manufactured
• (still under research)
• Artificial muscles
• Artificial arteries
• Structural connectors

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Advantages of auxetic materials

• Increased shear stiffness
• Increased plane strain fracture toughness
• Increased indentation resistance
• Superior to conventional materials for many
  practical applications