Question:
Maybe this is a stupid question, but here goes. Take a infinitely
long round bar with a single annular notch around it's circumference
(just like the type of notched bars found in stress concentration
factor tables and shown in the figure below). This notch gives the
bar a maximum stress concentration factor
Answer:
you have a solid round bar of x diameter with a notch d deep -
you have a solid block with a hole of x diameter at its center which has on
its circumference a notch d deep -
background - basically, stress concentration is used to derate a material's
abilty to carry stress without failure when it is subjected to a large amount
of cyclic energy where any single cycle of that energy will not exceed the
yield point of the material - which requires energy be delivered to the notch
area
it is unlikely they will have the same stress concentration factor for a like
load, since one is for a key-way type cyclic load, and the other for a
tension-compression or bending cyclic load -
the application of cyclic bending on the block would not induce appreciable
stress on the internal notch like it would if the notch were on the outside in
the stress-energy area
y is not equal to x any more than an apple is an orange -
as the problem is presented, they respond to different kinds of loads, and
the same type of cyclic load put on each will not cause the stress
concentration factor to come into play in one.
