Unformatted text preview: Auxetic Materials by: Zahra Elkassabgi What's Poisson Ratio? Ratio of axial and lateral strains Formulated so most materials with positive value = x = y z z What are auxetic materials and their properties? Materials with a negative Poisson Value Density may vary from onetrillionth the density of air or 100 billion times air Formed 460*F or 10,000+ heat of white dwarf stars Auxetic v. Normal materials Auxetic materials
Larger when stretched Normal materials Smaller when stretched Smaller when compressed Larger when compressed Applications of Auxetic materials Nature Manufactured (still under research) Neutron stars White dwarf Skin of a cat Artificial muscles Artificial arteries Structural connectors Advantages of auxetic materials Increased shear stiffness Increased plane strain fracture toughness Increased indentation resistance Superior to conventional materials for many practical applications References http://www.dallasnews.com/sharedconntent/dallas/healthsciences/stories http://silver.neep.wisc.edu/~lakes/PoissonStru.html http://silver.neep.wisc.edu/~lakes/PoissonEnd.html http://silver.neep.wisc.edu/~lakes/Poisson.html ...
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- Spring '08
- Strain, Supernova, White dwarf, Neutron star, auxetic materials