## Combining Stresses

## Combining Stresses

(OP)

Hi All,

I need help calculating the combined stresses (max/critical stress) on the journal of a ball screw to determine FOS. I got the torsional stress and the axial stress (compression and tension), but I cannot remember how to combine them. I am trying to refresh on Mohr's circle from class over ten years ago, but admittedly it is throwing me for a loop. There is no bending stress or other shear stress, just pure axial and torsional, so it should be the same around the shaft circumference. Can anyone please help?

I need help calculating the combined stresses (max/critical stress) on the journal of a ball screw to determine FOS. I got the torsional stress and the axial stress (compression and tension), but I cannot remember how to combine them. I am trying to refresh on Mohr's circle from class over ten years ago, but admittedly it is throwing me for a loop. There is no bending stress or other shear stress, just pure axial and torsional, so it should be the same around the shaft circumference. Can anyone please help?

## RE: Combining Stresses

## RE: Combining Stresses

## RE: Combining Stresses

Engineers, think what we have done to the environment !https://www.linkedin.com/in/goutam-das-59743b30/

## RE: Combining Stresses

Have a look at this site https://academic.uprm.edu/pcaceres/Courses/MMII/IM...

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

## RE: Combining Stresses

## RE: Combining Stresses

## RE: Combining Stresses

oh, I see it (on pg9) ...

maximum shear stress is (p1-p2)/2, the radius of mohr's circle; = (135--71)/2 = 103

another day in paradise, or is paradise one day closer ?

## RE: Combining Stresses

The 103Mpa is the centre of the Mohr circle, or the radius arm if you like (171 + 105)/2

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

## RE: Combining Stresses