Discussion Forum

You can select the same boundaries as both source and destination in a contact pair.

Dear Dr. Sonnerlind,

thank you for your kind answer. I've already done it, but during the simulation, the wings penetrate each other. I prescribed a displacement applied to the inner surface of the membrane in order to make it expand. It does not converge when I prescribe displacements in the normal direction higher than 0.009 mm (in addition to the penetration issue). Can you give some advice, please? I leave the images attached.

PS: I ran a pre-stretch study first since I was using membrane physics.

Hi,

This is difficult to guess. One possible cause is that wrinkling occurs somewhere along the unfolding process, so that you jump to an unphysical state. Currently there is no way to handle wrinkling in the Membrane interface. In the next release (later this autumn) that will be possible.

Another possibility is that the search distance in the Contact Pair is too small. You can adjust that manually.

Finally: Does it help to reduce the parameter steps? Or is there never any contact at all?

BTW: It looks like you have a threefold symmetry. Would it not be possible to reduce your model size by employing cyclic symmetry conditions?

Dear Dr. Sonnerlind,

I´ve tried to impose a displacement higher than 0.009 mm by using the ramping technique - I defined the displacement in the normal direction as 0.1 x parameter, and added a study extension to make it increase linearly. I applied this displacement to all the boundaries since it is intended to mimic the inflation of the balloon for the deployment of a stent. At this moment, I have severe penetration even with this small displacement... Regarding the cyclic symmetry conditions, I was not able to find this possibility in the membrane physics. I search in the physics menu, but without success. Can you please tell where should I look for?

Thank you so much for your kind replies.