$3.$ Putting Stresses Together $$ Part $1$: The same type of stress acting in the same direction can

be added together. A normal stress due to an axial load $(=$F$/$A$)$ can be added to a normal

stress due to a bending load $(=$Mc$/$I$)$ can be added together IF they act in the same

direction. Two shear stresses that act in the same direction can be added together.

You cannot directly add a shear stress to a normal stress of any kind. You cannot directly

add a normal stress in the x direction to a normal stress in the y direction.

Recall that both bending normal stresses and torsional shear stresses are at a maximum at

the surface and go to zero at the center.

For this problem, the bending and axial normal stresses act in the x direction. There are no

normal stresses in the y direction. The maximum bending normal stress is $20$ MPa and is

tensile $(+)$ on the top and $(-)$ on the bottom. The torsional shear stress is $60$ MPa and is

positive. The axial normal stress is $5$ MPa.

Draw something simple $($cut out of a rod with a circular cross section showing the stresses

and directions. Find the normal and shear stresses acting at $...$

Point A on the top, Point B on the axis at the center, and Point C at the bottom of the part