Slide
8
Now
lets use the theory to examine in further detail the shear
stress distribution in a shaft under torsional loading. We already
know that the shear stresses are directly proportional to the distance
from the center. It means that, for any circular shaft, the shear
stress would be maximum for an element which is farthest from the
center. The figure on the left shows the shear stress distribution
in a solid shaft. The shear stress is zero at the center while it
is maximum at the surface. The figure on the right shows the distribution
of shear stress for a hollow shaft. The shear stress is minimum
on the inside surface and maximum on the outer surface. As the thickness
of the wall of the shaft decreases relative to the shaft diameter,
the difference between the stress on the inside and outside of the
shaft decreases and you obtain a more uniform stress field.
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