What is the different between the max stress and the von mise stress

[Lorens]

What is the different between the max stress in a structure and the von mise max stress in the same structure?

Kindly Lorens

 

[arildno]

I'm not quite sure if I'm answering your question as you want, but:

1. From my hazy recollection, the von Mieses "(max) stress" in a structure is the YIELD criterion of the structure; i.e, if the local stress exceeds that value, plastic flow will occur.

2. Max stress in a structure is simply that: the maximal stress value in the structure.

Clearly, the max stress in the structure must be below the von Mieses yield criterion to ensure that plastic flow does not occur.

 

[Lorens]

But in Fem you often look into the von miese stress, and you can list the von mises stress for the diffrent nodes ...

 

[arildno]

Hmm..but that would surely mean the material has non-uniform properties (and, hence, different yield criteria)?
It is in principle unproblematic of making a non-constant yield stress function. In that case, the requirement is that the local stress does not exceed the local yield criterion.

I'll see if I get someone else to look in on the thread..

EDIT:
As kindly provided by another member, perhaps your problems are resolved by taking a look at:
http://www.engineersedge.com/strength_of_materials.htm

 

[buscae]

Hi All
I m new here, I have few basic queries, if anyone can clarify on same.
Que1):-For any linear static FEA analysis,w hy do we consider mostly Voin Misses stresses?Why not Principal or any other stresses ?
Que2):-Does Epsilon Values depends on elasticity or Density?