Slide
9
We
might ask the question "Do all materials fail in a similar manner
when subjected to torsional Loading?" As you will see the answer
is no. To understand this you will remember that whenever a structure
is subjected to torsion, the elements are in a state of pure shear.
By considering the transformation of stresses, this state of pure
shear, is equivalent to a state of pure compression and pure tension
on planes rotated forty five degrees to the axis of the
shaft. One implication of this stress state is that if the material
is weak in tension, it will fail along a plane forty five degrees
to the longitudinal axis of the shaft. However, if the material
is ductile, meaning that it can deform in shear before breaking,
it may fail along a plane ninety to the axis of the shaft.
|