Stress Stiffening 1

[KSshopper]

I have a model of a pressure vessel and want to run a solution with stress stiffening. I'm primarily experienced with ANSYS, but the model I have was developed using PATRAN for a NASTRAN solver. I didn't see anything in the user manual under stress stiffening. I have to assume that NASTRAN/PATRAN has a way to include this effect. Any NASTRAN users out there have the answer?

Thanks

Phil

 

[scofie]

For thin walled vessels, if by the term "stress stiffening" you mean membrane tension behavior, this can be done with PATRAN/NASTRAN using the "non-linear static solution" (I believe it is SOL 105?). In PATRAN, you would want to click the toggles to activate large displacements and follower forces under the Analayis method selection menus.

If you actually mean performing an analysis with strain hardening of the material past yield, PATRAN/NASTRAN also allows entry of the stress-strain curve for a material for a non-linear analysis including strain hardening.

 

[KSshopper]

Scofie:

thanks. I did mean the membrane tension behavior. Thanks for the reply.

 

[rhodie]

You aren't THE Phil Condit, are you?

Are you a native of Berkeley, Calif., born on Aug. 2, 1941, and did you earn a pilot’s license at the age of 18?

 

[gio1]

The Nastran sequence for stress stiffening effect is SOL106 but is implemented only with 1D and 2D elements (I assume your pressure vessel is made of shells, so should be ok).

Gio1

 

[RPstress]

NASTRAN bricks should run non-linear ok. One part of the manual says not to use mid-side nodes, though.

 

[Sparweb]

rhodie,
I seriously doubt that Phil Condit, the CEO of Boeing, is doing FE stress analysis.
If he is, then I envy him even more!
One of them will be giving a lecture to the RAeS in London in November. There's your chance to find out which!

STF

 

[rhodie]

lol


wishful naiveity on my part maybe...