lattice girder buckling

[laceratio]

hi all,
i'm modelling a lattice girder with plate because i want to find the bucklin Pcr. but with plate modellation i find not the pinned Pcr but the encastre Pcr.
some suggestion?
if someone want i can send him the model to a better understanfing.
regards
LP

 

[MER66]

please send to me your file(cae and jnl )

 

[MER66]

erfani.mohsen000@yahoo.com

 

[MER66]

hi
I see your model . you have some problems in your geometry
1_ when you use shell section with thickness you must be compute gap between element of beam in part1
2_ orientations in connection point between beam and shell is not same direction

you can find your problems when use beam render and shell render in :

Assembly : view/ assembly display option / at end of general tab click Rendel Beam Profile , Render Shell thickness
visulization : view / odb Display Option / click Rendel Beam Profile , Render Shell thickness

Mer66

 

[laceratio]

thanks mer66, i hope i didt your suggestion in the right way:
1) i changed the shell offset and now all the plate section are alligned.
2) i increased the gap between shell model and beam model
3) i also changed the material orientation of the shells and beams so now they are equal, and i also changed the beam orientation of the beam so now they are alligned with the shell's.
the results of the buckling step didn't significantly change.
i think in the plate model there is more stiffness computed than in the real lattice girder.
what do you think about?
i've already sent you the changed file.
Thanks
Luca

 

[MER66]

Hi
I see your new model ,its bether than old model
if you can all of the model change to shell and element type change to hex structure
and seperate all of the element of model and use from assembly and interaction
you can simplify your model and analysis critical region