Bike Frame Analysis (w/Shells?)

[ecosgriff]

I have designed a recumbent bike frame, and would like to analize it using Pro/Mechanica. We will be constructing the frame out of welded 1.5"OD x .020" tubing, 1/8" Plate Gussets, and bonded lugs (See the picture...). I am unsure of what types of elements and connections I should be using for the problem.


I have tried Beams, Mixed solid/shell, and solid elements. The beam model resulted in an unspecified fatal error, and told me to contact tech support. I tried an entire solid model, but it was huge. I ran a quick check, and gave up after the mesh had not been completed in over an hour. Mixing shells and solids seems promising, but I cannotget all of the joints to work out properly. I haven't gotten the fish-mouth joints and the bonded lug joint to work at the same time yet.


If anyone has some advice, I would appreciate it. I'm running an academic version of WF 3.0, with integrated mechanica. The computer has Pentium D 3+GHz Processors and 2Gb RAM. Thanks for your help!!


-ecosgriff

 

[ecosgriff]

View attachment 3173

 

[pramit.associat]

dear friend ,

Just go for direct modelling & assign joint constraints(weld + gaskets) & mesh with tetra .I think this may solve your problem.

with regards
PRAMIT

 

[headrush]

Since it's Friday you could run the solids model over the weekend.


A shell model would be much more efficient. You will need to pay attention to where your shells are located and if midplane you will need to manually specify the bond surfaces. It probably won'tbond automatically because the shell surface will not mate with the internal surfaces of the lugs (because of the offset between the midplane andthe outer surface of the tubes).


Note: I have never performed a shell analysis in mechanica.