How to explain von Mises

#1

SOURCE
https://www.eng-tips.com/viewthread.cfm?qid=266783
Please click through the source URL above to read the entire page’s discussion on Von Mises. Below is a snippet of the entire discussion.

QUESTION

I am incorporating customer comments into a calculation. The calculation was done in a FEA program using von Mises. The purpose was to show that the mounting brackets attaching directly to the walls were of sufficient design to handle the applied loads. The reviewer is a structural engineer who is use to seeing these calculations done according to allowable tension, bending, flexure and shear. What I keep getting back from him is "The allowable Bending and Shear stress is lower than the allowable tension. How can I use the allowable tension to justify all forms of loading.”

REPLIES

Ron
If I’m understanding your question correctly, you cannot justify comparing only the allowable tension if you have both shear and bending occurring as well. You have to check all, and you have to check interaction as well (for instance, tension + shear on the same section). The lower value prevails.

Look at the von Mises results in a uni-directional or bi-directional case and compare those to allowables. The structural engineer will better understand those as they compare directly to what normally checks.