Question:-
Wahl stress factor takes into account
Option (A)
Direct shear stress
Option (B)
Torsional shear stress
Option(C)
wire curvature effect
Option(D)
Direct shear and wire curvature effect
Correct Option:
(D)
Question Solution:
Since the spring rod is bent into a curve the shear stress on the inner surface is more than the shear stress developed on the outer surface. To take into account the curvature effect. Wahl’s correction factor may be applied and maximum shear stress can be calculated
tmax = Kw (16WR/pd3)
Where kw is wahl’s correction factor and is given by
Kw = {(4c-1)/(4c-4)+(0.615/c)}
Where ‘c’ is the spring index
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