Weird displacements contours at initial state

Hello! I get to equilibrium next model with no problem but displacement and velocity contours do not seem like equilibrium is reached. I cycled the model 10000 steps more but any change. In elastic cmodel contours are horizontal but when change to Plastic-Hardening this situation arise. I´d appreciate if you can help me, thank you in advance.

Are the boundary conditions ok? i mean… roller at elastic and fixed in plastic?

For the PH model, you need to set the initial principal stresses (stress-1-effective …) .

Thanks Matias, yes boundary conditions were ok, the problem was I did not set the initial principal stresses for the PH model.

Thanks Huy, I set the initial principal stresses for the PH model and now contours plots are ok!

Carlos, I solve the model as elastic to reach the in situ stresses, and then rescue the prinicipal stresses to use for the plastic hardening by fish. Cheers

hello Huy,
The initial principal stresses in PH model puzzle me a lot.
Is it possible to solve the problem inwhich the soil is M-C material with “model solve elastic”, and then change the M-C to PH without assigning the intial principal stresses?

You need to set the initial principal stresses for PH model because it’s a stress-dependent model.
You can have a look on the example below in the FLAC3D documentation.
Reinforced Tunnel Excavation (FLAC3D) — Itasca Software 9.0 documentation (
As you can see, the principal stresses are assigned via the function “iniprin” which can be found in the “FishTask” file of this example.

than means, after I set the model to PH, we must assign the principal stress from the m-c model just like below?

fish define iniprin
    loop foreach z zone.list
        if zone.model(z) == 'plastic-hardening' then
            zone.prop(z,'stress-1-effective') = zone.stress.min(z)
            zone.prop(z,'stress-2-effective') =
            zone.prop(z,'stress-3-effective') = zone.stress.max(z)