Learning Forum

[Haiquan]

Hello

I am trying to perform a prestress explicit simulation but face Negative element density error and a warning in explicit as shown below. The model includes a socket and a screw(simulation uses ¼ model). 

First step in static is a large deformation interference fit simulation between socket and screw.

Second step in explicit is to extract the screw from socket

By the way, the mesh is completed in Hypermesh, and if I suppress the prestress condition in explicit, there is no problem to finish the explicit simulation. I have attached my wbpz file.

Thank you in advance! Hope everything is doing well with you!

[Haiquan]

Any comments on my issue? By the way, the Ansys file version is 19.2, thanks!n

[peteroznewman]

ArraynI have not seen Static Structural prestress an Explicit Dynamics model. I tried several variations of your model using 2020 R1 and the Explicit Dynamics solver immediately shows the error Invalid Boundary Condition. I don't know what that means. It gives that error no mater what boundary conditions are in the Explicit Dynamics model, none or the same as Static Structural. Hopefully, someone else will answer.n

[Haiquan]

Thank you very much for your comment! I will try 2020 R1 to see if I have the same problem with you.n