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normal stresses that are evenly distributed on it and equals to the
ratio of the axial force and the cross-sectional area.
During the tensile and compression there can occur a
heterogeneous stress state. Consider a rod with variable cross-
sectional area (fig.2.5). Here are tensions at different points with
different values and different directions.

Figure 2.5
For example, if the rod of a rectangular section with a constant
thickness b and the width  xh , slowly that are slowly changing
according to the linear law, then stresses, that are normal to a
curved section, have a radial direction and can be determined by
the following formulas:
- stress in the fiber that makes an angle  with the axis of the
rod:
N cos 
  x , (2.6)
  1 
br   sin 2  
 2 
- stress at points on the axial fibers:

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