Hello everybody!
I apologize in advance, but I’m encountering serious troubles trying to apply residual stresses as an initial condition.
I am performing simulations that involve plastic deformation on gears in Salome_Meca with Code Aster (STAT_NON_LIN) and I would like to insert as initial condition the residual stresses that characterize the surface of such gear.
I already tried to insert the residual stresses using CREA_CHAMP to create the field of stresses and then PRE_SIGM to apply them. With this two keywords, the stresses are applied after the first timestep. By adding also ETAT_INIT and applying the field of stresses with this, they are applied also at time instant 0.
What I obtain is that the residual stresses are applied correctly only at time instant 0. After the first time step, they are changed by Salome as it needs to put them in equilibrium. I think this is because I need to insert also the corresponding residual strains, so that equilibrium is respected and the software does not need to change the stresses, but that is just my hypothesis. Indeed, I tried to apply also the residual strains (directly in the PRE_EPSI menu) and again, Salome changes the stresses.
As a result, I am in the condition of not knowing how to correctly apply some residual stresses that are not changed after the first timestep.
How would you do it? Are the residual strains actually a necessary initial condition to have residual stresses applied correctly?
If you have some suggestions also for just one of the questions this would help me a lot.
Thank you all in advance for the help!