sentences:  the truncated cone, the worn sphere, rough profiles, hollow cylinders, etc.can be found in 
  
  An elastic sphere of radius formula_1 indents an elastic half-space where total deformation is formula_2, causing a contact area of radius 
  
  The applied force formula_4 is related to the displacement formula_2 by 
  
  where
  
  and formula_8,formula_9 are the elastic moduli and formula_10,formula_11 the Poisson's ratios associated with each body.The distribution of normal pressure in the contact area as a function of distance from the center of the circle is
  
  where formula_13 is the maximum contact pressure given by
  
  The radius of the circle is related to the applied load formula_4 by the equation
  
  The total deformation formula_2 is related to the maximum contact pressure by
  
  The maximum shear stress occurs in the interior at formula_19 for formula_20.