buckling load
buckling load
(OP)
I want ot simulate Buckling analysis in Pro/Mechanica, under hinged-hinged condition. I Applied constraints (Hinged) on the both the faces, and try to apply a load on a face but ........
Pl. Guide me.
Thanks in advance.
Nikhil
Pl. Guide me.
Thanks in advance.
Nikhil





RE: buckling load
David R. Dearth, P.E.
Applied Analysis & Technology
E-mail "AppliedAT@aol.com"
RE: buckling load
I want to run a buckling analysis on a column, having hinged support at both the ends & axially loaded compression) at one end and I want to find Critical load (Fcr) for this condition. Which is theoratically equal to (E*I*(PI/Leff)^2) and in PM/Str. it is equal to F*Buckling Load Factor (B.L.F.).
Please guide me, how & which constraints & loads, i apply to solve this problem.
RE: buckling load
If you're using solids, I think you'll need to create a line on the top surface and the bottom surface, and apply the above constraints to these lines. Otherwise you can't get a hinged condition - if you constrain the 3 trans dof on the bottom surface, you have also constrained all 3 rotation dof.
Also, you can go to the knowledge base on the ptc website, search under 1. suggested technique, 2. mechanica, 3. buckling, there will be a document titled "suggested technique for buckling analysis" -- tutorial for doing buckling analysis on a coke can.
Hope this helps...
RE: buckling load
In my case I have a pipe shell column. I modeled it hinged/hinged as you suggested and applied the load at the top. The static analysis went ok but when I tried to run the buckling analysis I got a fatal error. Any thoughts why?
Thanks!
Rainier
RE: buckling load
My shell idealization blf = 12.3. As a check, I tried modeling it as a beam idealization, and it went through without any problem. My beam idealization blf = 6.3. The shell/beam idealization blf ratio = 2 is quite large. Any idea why is this so? (The blf=6.3 is also what I get by hand calculation using the AISC greenbook)
Thanks again!
RE: buckling load
How many elements are in the model? Sometimes mechanica creates really coarse meshes and it's necessary to adjust the autogem settings and/or add some fixed points to force it to create more elements. Is this it, or should I give it some more thought?