SCAS Plate Stiffeners

[mohammed43]

I have modelled two plates with similar properties, boundary conditions & loading. And one assigned one plate with plate stiffner and the second plate with beam section (similar to stiffners) as stiffners.
But the results for two differnt plates vary a lot.
Can anyone help..

 

[SethGuthrie]

For the first one the stiffness is smeared in the direction of the stiffeners and anisotropic plate theory is used. In the second (with beam elements) the stiffness is obviously not smeared and isotropic plates are used between the stiffeners.

 

[mohammed43]

thanks..
I had read in the sacs manual that properties are reported for stiffner plates but stresses are reported separately (flate plate & stiffner separately). I didnt understood this part exactly, if stresses are reported separately then how to check the actual stress.......??
Also can you tell me the solution for isotopic & anisotropic.. I mean to ask how to make the stresses resemble if I use stiffner plate & beam sections as stiffner..

Thanks for your help..

 

[SethGuthrie]

The reports in the list file are in two parts….plates and stiffeners.
It’s difficult to match the solution for stiffened plate where the stiffness of the stiffener is smeared and a stiffened plate where the plate and the stiffener are explicitly modeled. The smeared model is usually adequate for a global analysis but not for a detailed analysis – for example a blast wall.

 

[mohammed43]

Thanks..

If Iam not asking too much.. Can you please elaborate the smearing of plates concept. I havent studied FEA..

You mean to say if we want to do detail(local) analysis, we need to use beam stiffners instead of plate stifnners..

Thanks for your time..