Pro-E Slinky Model with motion

[Recon1775]

Has anyone ever come across or created a model of a slinky that can be moved in a motion analysis?

 

[Guest0527211403]

I don't think this can be done, since it would require the model to deform. Motion analysis only deals with solid bodies for kinematic/kinetic analysis, so your slinky model would not be able to 'slink'.

The physics behind a slinky are wonderfully complex. There is constant interaction between gravitational potential energy, forward kinetic energy and stored spring energy. But don't tell that to your kids because it might take away from the fun of the toy! (actually to me it makes it that much more fun )

 

[davidh729]

There may be a way to simulate it with mechanism dynamics. You may be able to drive flexible dimensions with the spring components. Don't know if this would work, but it might be worth a try. The only time I've seen something like a slinky simulated is with an FEA package with an explicit solver.

Dave Hyman
Mechanical Engineer

 

[JohnAndrews]

Why do you want to do this?
Do you have a specific engineering application which requires similar behaviour, or are you bored with your current job?

 

[Recon1775]

I actually need the motion for a flexible duct analysis, so I just threw the question out without going to much into it. The duct would move as a slinky or spring where one side is in compression and the other side in tension.

 

[Guest0527211403]

Ah, I see now.

This can certainly be modeled in Pro/E (helix along a curve method) as you have likely already done. But part flexibility "breaks the rules" of motion analysis in Pro/E.

Depending on what you are trying to get out of the analysis, you may be able to use BMX to perform a sensitivity study, provided that the trajectory curve is modeled such that you can emulate it's motion by changing a few dimensions.

Alternatively (this is mostly if you want to make a video), you can set a relation (i.e. X=X+1) to have the duct "move" with each regeneration, then snap off a JPEG. Mapkeying this really helps.

Good luck!

 

[JohnAndrews]

You can try and simulate this with mechanisms using multiple parts like a chain and joints with rotational limits

 

[Recon1775]

Thanks for the advice!
I'll try them all and let you all know if they work out.

Thanks again!