How to model an assembly for fea?

[melcys]

Hello!

Assembled components/ interlocking components (interlocking bars, coupling etc) are always regarded as one component in fea or at least the elements of different components in an assembly are sharing the common nodes where they meet. However, in real life, when the assembled components are subjected to rotations or motion, the coefficient of friction between the components changes and the assembled components might slip against each other. I can’t model contact element, because assembled components usually have very small tolerances for tight-fit purposes. How should I model?

Regards, mel

 

[ishvaaag]

I assume you are describing a problem in mechanical design we have also in mere structural design: the programs are all perfectible and are all being perfected. Surely everyone devises things that would make programs better, and your question pertains to such demands.

I remember a (by now) modest mu-SAFE program modelling fasteners and you could even put parts geometrically apart, I think to remember, long rigid links allowing for the proper degrees of freedom produced the proper analysis (more orless, and for the parts). Rigid links between parts or to some reference fixed points of some boundary conditions may help some times, but for others will marr the behaviour of some structural part you want to analyze.

So in the end my advice is to seek one program able to easily model such things. I assume the mechanical big programs must be able to do this -easily I assume not- I think the motors rotating seen in ads are no always figment of just illustration imagination, but a reality in the industry. Normally, a program with a good capability in this context will be glad in making it very explicit...it would be seen quite clear by reading the manuals or tutorials.

 

[dubourg]

Hi Melcys,

Are you talking about Assembly Stress analysis while the components are moving (Kinematic or so) ?

 

[melcys]

hello! dubourg,

just any sheer ideas, how assembly are modelled whether it is for static or dynamic. But now, I'm investigating how an interlocking component, rotating at a speed, should be modelled

regards, mel