Sean Harvey
Ansys Employee

Hello Helen,

You can change material properties between load steps by using the ‘MPCHG’ command with certain limitations such as material properties cannot be changed from linear to nonlinear, or from one nonlinear option to another. So for this, you don't need restart.

Ekill and ealive also do not need restarts and they are natively exposed inside Mechanical if you are using Mechanical that is.

Single frame restart is the original method of restarting in APDL. In fact if you are in MAPDL, you solve a load step, then add some loads, and solve again, you are using a single frame restart. There are all the files such as esav,full,db, etc. needed to do this.  You may have seen input files for mapdl that have multiple solve commands. That doc you shared is a good resource that if you are using mechanical, it will naturally set the model up for multiframe restarts.  With multiframe, we can have multiple points, but there are some limitations as listed in that help doc.

So, in your case, you can use single frame restart and just put in mpchg in a command object, and use ekill and alive natively. The code provided to delete the rdb and turn of restarts should not be necessary if you go to Analysis Settings> Restart Controls> Generate Restart Points to No.

MPCHG is valid in /solu, so you don't need to even leave /solu to go to /prep7

Keep in mind Mechanical deletes the single frame restart files (and other files) by default after the solve, and you can change this under Analysis Settings > Analysis Data Management> Delete Unneeded files to No

Good luck!

Sean