Pure shear

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In mechanic and geology, pure shear is a three-dimensional homogeneous flattening of a body.[1] It is an example of irrotational strain in which body is elongated in one direction while being shortened perpendicularly.[2] For soft materials, such as rubber, a strain state of pure shear is often used for characterizing hyperelastic and fracture mechanical behaviour.[3] [4] [5] A rod under torsion is a practical example for a body under pure shear.

Pure shear stress-strain relation[edit]

Pure shear stress, denoted , is related to pure shear strain, denoted , by the following equation:[6]

where is the shear modulus of the material, given by

Here is Young's modulus and is Poisson's ratio. Combining gives

See also[edit]


  1. ^ Reish, Nathaniel E.; Gary H. Girty. "Definition and Mathematics of Pure Shear". San Diego State University Department of Geological Sciences. Retrieved 24 December 2011. 
  2. ^ "Pure shear". Answers.com. Retrieved 24 December 2011. 
  3. ^ Yeoh, O. H. (2001). "Analysis of deformation and fracture of ‘pure shear’rubber testpiece". Plastics, rubber and composites. 30 (8): 389–397. doi:10.1179/146580101101541787. 
  4. ^ "Where do the Pure and Shear come from in the Pure Shear test?" (PDF). Retrieved 12 April 2013. 
  5. ^ "Comparing Simple Shear and Pure Shear" (PDF). Retrieved 12 April 2013. 
  6. ^ "Strength of Materials". Eformulae.com. Retrieved 24 December 2011.