General advice need regarding assembly analysis

[ScottAW]

I've been using Pro/Mechanica fairly succesfully for the past few months and now need to analyze a frame structure that is essentially a backbone of 2'x4' slab of steel, held up with gusset pieces to a base. There are some masses cantilevered off the backbone, and all the parts are bolted together.

I need to analyze the entire assembly, but haven't played around with specifying joints and such on Pro/Mechania yet. (wildfire version) What is the best approach for this? Do I need to specify my part connections, or is there a default type of connection that Pro/Mechanica assigns?

Thanks!

 

[LTR]

Mechanica assumes contacting parts are welded unless otherwise specified. I think this would work for a bolted joint if you analyze the bolt loads based on your FEA results to make sure you haven't exceeded the sheer or tensile strength of your bolts.

 

[mloew]

ScottAW,

Please see the thread Simulating bolted joint connections (thread828-73304). LTR is correct regarding the default assumption of a "welded" connection.


Best regards,

Matthew Ian Loew
"Luck is the residue of design."
Branch Rickey

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Seacon]

As LTR mentioned, if you assemble the parts by mating or aligning surfaces etc, the assembly will assume that the two parts are bound at that specific joint. This would appear to be okay for the bolted joints but what about the other adjoining components you mentioned?

An easy round way this is to adjust your assembly alignment;

Make sure that when you are locating a new component to an existing assembly, mate or align DATUMS or AXES.

Obviously this may not be as convenient as using existing surfaces, but spending several momments creating new datum planes will allow you to perform analyses on assemblies.
Whan you switch to Mechanica mode from Pro/Engineer, it will warn you that you have several components rather than one full assembled component. Check this number is what you expect!