# Conditional Contact

Hi,

my name is Klaudia and I am writing my diploma thesis at BMW Group with AnyBody.
[FONT=Arial]We got a model from you that visualizes with our markers how a person get in and out of the car. (AnyBody version : 4.0.2, GaitUniMiami)[/FONT]
We create a seat which supports the model and a conditional contact between seat and pelvis with a virtual cylinder with radius and height. Now we want that the target point is inside this cylinder a contact force can be present. But it don´t works.
Can it be that in our model are forces, which stabilize the model[FONT=Times New Roman], e.g. AnyReacForces why the conditional contacts are not measured?[/FONT]
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[FONT=Times New Roman]Best regards[/FONT]
[FONT=Times New Roman]Klaudia[/FONT]

Hi Klaudia

You are right, if you have anyreac forces acting on the pelvis you may not see any forces in the conditional elements because there are no force left to carry since the reaction force will take it all.

I do not think this the case in this model though, if you look in the “JointAndDriversOptimized.any” i think you will see that all reactions are set to be Off meaning that they do not carry any reactions.

If you have no force in the contact element but the model is running the inverse analysis then clearly something must be provding some forces. otherwise the model would not be able to run the inverse dyn. analysis.

So which reactions have you supplied the model with?

If the reactions in the contact elements are not present there can be these reasons:

[ol]
[li]the model does need them other reactions carry the load[/li][li]The target point is not within the virtual cylinder, to check this there is some measures inside the contact element named “userdefinedmeasures” that lets you check that this values is with in the radius limits. there are similar checks on the height low and high i think.[/li][li]It is very important to be aware of the normal direction of the baseobject if this is not set to the direction you intended it may not work.[/li][/ol]
I have found a posting in the AnyScript archieve which includes a bit more explanation to the use of the contact element please find it at this link:

http://forum.anyscript.org/showpost.php?p=9537&postcount=29

It has explanations on all the items which gos into the contact element.

If it continues to cause problems please try to do a simple one segment model, making use of the contact element just to get a feeling on how they work.

Hope it helps you move on.

Best regards
Søren