Rigid link versus weighted link

[opavot]

hello Everybody

I have a model where I want to assign a mass , but this mass is outside the model.

First I have created a point where my mass will be located but I don't know what is the best solution to link the point and the model

Use a rigid link or use a weighted link ????

Many thank for your help

Olivier

[MatsLindqvist]

Weighted link allows the reference geometry to deform, the rigid link does not. I'd use weighted link if I can (it's ony available in the advanced version of simulate).

A limitation of the weighted link, is that you can't apply a constraint to the dependent point, but there's a workaround for that. This shouldn't be a problem in your case since you want to apply a mass.

/Mats L/Product specialist, simulation tools/Econocap Sweden/

[opavot]

Dear Mats

Many thanks for the explanation

OP

[MatsLindqvist]

Ici j'ai fait un petit presentation de ce sujet:

http://www.youtube.com/watch?v=keMLlyec4B8

En suedois, mais je crois tu comprends...

/Mats L

[ptc-1901164]

Hello can u describe the workaround for constraining a weighted link on a point ?

Thans a lot for response...

[JonathanHodgson]

You need to create two points (having them slightly separated makes it easier to build).

One forms the dependent node of the WL; the other is constrained to ground; and they should be linked by a spring element.

This needs to be set to Advanced, where you can define all six stiffnesses (three translation, three rotation). You may also need to set some direction vectors if you make your points coincident. You should make the stiffnesses just stiff enough to avoid affecting your results noticeably: choose an acceptable displacement (say 0.01 mm) and divide the load by this displacement to find the required order of magnitude.

HTH!

[ptc-1901164]

Thank you for your fast response first,

I think this could work....

[opavot]

Dear Mats

not easy to understand beacuse I don't speak the language

OP

[MatsLindqvist]

It describes three different methods to constrain a shaft subject to bending and torsion, using three different methods. I use regular constraints (erroneous), rigid links (correct, but yields unnatural stress distribution around constraints), and weighted links (correct, no unnatural stress distribution, but more complicated to create).

Video Link : 3069

[ptc-676952]

can someone share the original proe file to see the 3 methods.

[DenisJaunin]

Hello, NAPOLEON,

The topic has been reactivated, it would be interesting if your application file sharing could be heard.

This is a very interesting example, as we do not often see.

Cordially.

Denis.