Not sure why you do this (also be careful if it is used for something important, say design of structure), but here goes.
The only way of doing this is.
- Have one model with 3 steps.
- Define one kin. plasticity or bilinear iso. plasticity material. Set it with very high yield so it is basically used as the linear material as it will never yield.
- Define 3 steps. 1st step uses the material mentioned above with load, 2nd step goes back to unloaded, and 3rd nonlinear material step with load again.
- In the 3rd step change the material properties to the real plastic ones and not the very high ones used in step 1. This is done via command snippet (placed in the Solution tree) that is only active in step 3 (set step selection mode to number and enter below it step number 3). The nonlinear material shown below needs to be of the same sort of plasticity as in the material used in step 1 (so the one defined in engineering data)!
!change the below as needed for your own properties (they need to have the same plasticity so both need to be bilinear iso. Hardening plasticity here)
MP,DENS,2,7850, ! kg m^-3
MP,EX,2,200000000000, ! Pa
- Use solution combination to combine the results from step 1 (linear) and step 3 (nonlinear material).