For detonation related info, I am not sure I can discuss it here. Let me check on our restrictions.
[Q1] ” one’s error is “negative volume in solid element”, it looks like some elements of ground have sharp angles”
[A1] This already meant that you have inverted some solid LAG elms. The solution is wrong already. No sense to carry on. When mat fails, failed LAG elms get removed. You need to get proper mat failure data.
[Q2] error in above pic
[A2] I do not know this error – machine or platform related maybe(?) – you can check with your computer admin people(?).
[Q3] 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,
[A3] With LS-DYNA restart is never guaranteed even for a simple LAG model! For the ALE model with FSI it is not suggested. This requires a lot of time for debugging typically because the result mapping is never straightforward. This may be something requiring a support ticket. Not something that can be diagnosed on this platform.