Thanks for your reply! Please forgive me for not seeing your message until now, I want to use a metal ball penetrating into ground, and then put some explosive into the hole and detonate, so I think full restart can do this. I use two versions DYNA solver, one's error is "nagative volume in solid element", it looks like some elements of ground have sharp angles, they can continue in run1, but can not restart in run2, the other one's error is in the photo above. In my restart analysis, I only use stress_initialization to initialize the ground part, delete other parts and then add explosive and air part to make it become a FSI analysis, I can not understand that why the ground part elements are OK in run1, but negative volume or the above error in run2.
Thanks again and best regards,