Learning Forum

[Carlos Valle Noguera]

Hellos everyone,

I'm doing an impact simulation between a dental implant and a surface in transient structural, the problem that i'm having is that it doesn't detect when the impact happens and the bodies just trespass each other. I've already tried with setting the pinball region radius to include all the contact regions but it still doesn't detect it. 

I was wondering what could be the reason for that. 

I have also run into warnings where it says that the convergence value is lower than the threshold, and another warning saying contact status has experienced and abrupt change but the objects don't seem to make contact.

Thanks in advance for your help

[Chandra Sekaran]

The 'abrupt' change could be that the contact has moved past the pinball radius i.e. moved from 'near contact' to 'far open' contact status. Can you move the geometry so that it is in initial contact or use the 'adjust to touch' option in contact so that initially the bodies are in contact? Or perhaps you can use contact stabilization damping? This AIS course https://courses.ansys.com/index.php/courses/prevent-rigid-body-motion-in-contact/ has a nice ideas of how to prevent rigid body motion. 

[Carlos Valle Noguera]

I've tried adjust to touck and they still behave like rigid bodies and don't make contact, they just go through one another.

[Chandra Sekaran]

May be you can try a first load step with time integration (under analysis settings) turned OFF and with a small time value. The goal is to simply establish the initial contact conditions. I would recommend taking a look at the result of this load step (contact status) to make sure contact is established. Then start your transient from 2nd load step onwards by turning time integration ON.

[butres ali]

I've tried adjusting and tucking, but they still act like hard bodies; they don't make touch with one another and instead merely pass right through one another.

https://forum.ansys.com/forums/topic/problems-detecting-the-contact-in-an-impact-analysis-with-transient-geometry dash subzero