Event simulation - negative volume error

[18jhooles]

Hi there,

I am looking for some help, recently I have been attempting an event simulation similar to a car crashing into a solid wall. This will test my design. However, when attempting to run the simulation. I continue to get an error as seen in the photo attached, "negative volume", so, my next step was to see if anyone had the same issue. After trying to troubleshoot the issue using "validate" like the forums suggested, I am now stumped and wondered if I could get some assistance as everything through the validation tool, simplify, interference and everything I can think of that could be preventing the compute is not working. It is also worth noting that it copes with a static stress test completely fine, it is only the event simulation that it struggles with. If anyone can share some insight into what is going on, it would be greatly appreciated.

Kind regards

[mohammed.aliTDPXK · Accepted solution]

Hello @18jhooles ,

This is because of the excessive distortion of the finite element mesh has caused one or more elements to have a negative volume, which invalidates their results. This case happens when nonsensical loads have been applied to the model that cause it to deform beyond any reasonable expectations. While Autodesk Explicit has a large-deformation formulation that allows extremely large strains, there are limits to how far you can distort a model (example: you cannot turn a part "inside-out").

Please check the loads and constraints and also you need to add a proper element deletion criteria.

For more details please see : Autodesk Inventor Nastran 2022 Help | Add Element Deletion | Autodesk

[18jhooles]

Thank you so much, I decreased the initial velocity value and it worked!