Stress around circular hole

[ryan_struct]

Hello Guys,

I have a bracket with a hole and when I perform FEM analysis i get stress concentration around the hole. My question is can I use plastic stress field around the hole? And if i'm using plastic stress , to which value I will compare ? Do we have a code or standard reference stating that we can take the plastic capacity around the hole?

 

[FEA way]

Even with plasticity included you can use the von Mises stress and compare it with the material’s tensile strength for example. But take a look at plastic strains (PEEQ) as well.

 

[NRP99]

If you are using elastic-plastic analysis to check whether yielding is happening at hole of plate with hole case, then you may look for how much the area is going in yield strain of material. Besides your query is not crystal clear. Could you post some pictures of your results?

 

[rb1957]

are you using material non-linear FEA ? (so that it understands not to extrapolate stress linearly beyond fty)

the reality is that at a (any) hole is almost any structure there is a highly localised plasticity that has little bearing on the load capacity of the part. Once the plastic stress becomes global in the model (and not isolated local break-outs) then "the game's up".

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

 

[SWComposites]

Material?
FE analysis - linear or nonlinear?
Application - steel girder for building or aircraft spar web?