Ligaments, Wrapping and FDK

Main Forum
1

Hello again

Am I right with this assumption?:
If “AnyKinSPLine” is used to create Ligaments:

[ul]
[li]They can wrap over analytical surfaces[/li][li]Their lengths cannot be adjusted by a calibration study[/li][li]They cannot transfer forces in a FDK analysis, because it’s a kinematic measure sub class[/li][/ul]
If “AnyViaPointLigaments” is used to create Ligaments:

[ul]
[li]They cannot wrap over analytical surfaces[/li][li]Their lengths can be adjusted by a calibration study[/li][li]They can transfer forces in a FDK analysis, because it’s a force sub class[/li][/ul]

If Yes, is there a combination of both? Something like AnySPLigaments?

Thank you
MMMPPPMMM

2

Hi MMMPPPMMM,

Here are some answers:

Am I right with this assumption?:
If "AnyKinSPLine" is used to create Ligaments:

[ul]
[li]They can wrap over analytical surfaces[/li]> [li]Their lengths cannot be adjusted by a calibration study[/li]> [li]They cannot transfer forces in a FDK analysis, because it's a kinematic measure sub class[/li]> [/ul]If "AnyViaPointLigaments" is used to create Ligaments:

[ul]
[li]They cannot wrap over analytical surfaces[/li]> [li]Their lengths can be adjusted by a calibration study[/li]> [li]They can transfer forces in a FDK analysis, because it's a force sub class[/li]> [/ul]

This is not entirely correct.

You can create an AnyLigament object which will expect a kinematic measure. Here you can make use of an AnyKinSPLine.

This should work ok for applying a forces both in FDK and normal analysis.

The drawback of the AnyKinSPLine is that it is not possible to drive this measure, but as long you use it for applying a force things should be fine.

I am not sure why there is no built in class using the AnyKinSPLine ... but it using the approach i describe above should enable you to work around this.

Best regards
Søren

3

Thank you

I will give it a trial. :slight_smile:

Regards
MMMPPPMMM

4

Hello Søren

I want to try to implement your workaround into my model, as long as there is no alternative.

I have build a small Model with a “AnyKinSPLine” (Red) & a “AnyViaPointLigaments” (Purple).

Would be great, if you could explain me how to use the “AnyKinSPLine” as internal kinematic measure in the “AnyViaPointLigaments” to create a force that acts in the direction of the “AnyKinSPLine”.

And how is it possible to measure the length of the “AnyKinSPLine” (Red) at the beginning of the study?:

Thank you very much :slight_smile:
MMMPPPMMM

5

Hi,

Attached please find the modified version of your model.

It is very easy to make it because you have made it almost already!

As Søren suggested you before, you can just use AnyLigament class object with AnyKinSPLine class object.

Best regards,
Moonki

P.S) Could you please update your personal information including your real name?

6

Thank You very much!

7

Is it also possible to use AnyKinSPSheet as Kinematic Measure for AnyLigament.

I don’t have the software in front of me at the moment, so I’m asking here instead of trying it myself ;).

Thanks
MMMPPPMMM

8

Hello MMMPPPMMM,

You can use the AnyKinSPSheet similar to the AnyKinSPLine. The only difference is that you will probably need an AnyKinMeasureOrganizer in the AnyLigament to select a coordinate of the right string in the sheet. An example for this using muscles is shown in the class example which is linked in the reference manual of hte AnyKinSPSheet.

Best regards,
Daniel