Meshing/Element problems with beam sections

[kpt4321]

Hello all-

I am attempting to do analysis of a space frame (an automotive chassis composed entirely of tubes) using Pro/E and Mechanica. I have modeled the frame using datum points connected with datum curves, and am doing FEA using the beam sections capabilities of Mechanica.

However, with a recent iteration of the frame, I am running into problems in element creation. If I try to run an analysis it errors out ("Mechanica could not generate elements for all the entities in the model"), and using AutoGEM to create the mesh results in an error message stating that "the highlighted element edge is not associated with the highlighted curve." Multiple datum curves are highlighted (approximately half of the ones in the model) and they do not have any specific/distinct properties that I know of.

It is worth stating that all of my Mechanica knowledge is self-taught; they offer courses in advanced modeling at my university (which I have taken), but no instruction in terms of Mechanica. I have run many space-frame analyses before, and have not seen this error.

 

[kpt4321]

Some solution information, for the record:

The cryptic error message I was getting meant that there was a problem with the datum curves which I was using to define my beam sections. I do not know exactly what the problem was, likely an issue with an overlap or a gap between beams. I was able to resolve the issue by reming the problem features, and carefully redifining them from scratch. I am not sure what the specific error was being caused by.

Hope this benefits someone!

 

[Tgatica]

I have had good success using simple sketches. The trick is to define datum planes such that the sketch end points line up if the elements are not in the same plane. Alternatively you could define the end points with datum points then use "point to point" when defining beams.

Tony