Different Poisson’s ratios Shear stress at interface-bonding problems.
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22-Dec-2015 -
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Transcript of Different Poisson’s ratios Shear stress at interface-bonding problems.
• Different Poisson’s ratios• Shear stress at interface-bonding problems
• Less stress concentration when placed centrally
Load-Transfer
• Affected by bonding characteristics at interface– Frictional/adhesive characteristics– Orientation of interface relative to loading
direction– Surface microstructure/texture
• True only when bonded surface is perpendicular to loading direction
• Bonded case, both compressive and shear at interface, shear > compressive for small angles
• Press-fit, get a tensile hoop stress in bone to prevent expansion, and maintain equilibrium-abnormal loading
• Rigidity of stem affects– Bone stresses (may cause resorption)– Interface stresses (may cause loosening)
• Non-cemented stems tend to be canal filling and thicker---hence….(more stiff, more stress shielding)
• Bone stiffness-VERY IMPORTANT
SENIOR DESIGN??