Hi Armin, thanks for your reply. Unfortunately, I don't have access to ALH.
I found one helpful video How to Combine Distributed ANSYS Results After Solver Error/Crash - YouTube, which shows how to use Restart. One interesting question is that the latest ANSYS, eg 2020 or 2021, does not have the Tools Button to Read Results files （around 6:54 in the video). Do you know how to read the results files for Restart in ANSYS 2020? Thanks.