Hello

I'm currently trying to simulate an excation.

for that I need to simualte the following steps:

1) all soil, to obtain initial soil stresses

2) changing a soil region to reinforced concrete

3) deactivating soil regions of the excavated section

step 1 and 3 I have figured out how to obtain, step 3 specifially by using the interaction menu to activate or deactivate mesh elements or model geometry.

My current dificulty is figuring out how to implement to material change between steps for a specific region/part of the model.

I have so far understood that it has to do with creating field variables in the material interface menu, but I haven't been able to figure out how to specify in which step material changes or how to specify the region.

If someone could give a step by step explanation on how to do it, I would be very grateful!