How to set initial condition (initial displacement field) of the model, and does SOFA consider geometric nonlinearity ?

[SustechShenCong]

How to set initial condition (initial displacement field) of the model, and does SOFA consider geometric nonlinearity ?
I tried to use " DoFs = root.addObject('MechanicalObject', name="DoFs", position=InitialPosition) " to set the initial condition, but it failed !!! Help me !
Another discussion, does SOFA consider geometric nonlinearity ?

[hugtalbot]

Hi @10043816beau

You can specify the initial position using the position data field. It's strange that it failed. Could you share a simple example where it fails.

To impose a displacement (more generally boundary conditions) can be defined using ProjectiveConstraint, like LinearMovementProjectiveConstraint.

Could you elaborate what you mean by geometric nonlinearity? Do you refer on the element type?

[SustechShenCong]

The first problem, which was caused by my carelessness, has been solved.
Geometric nonlinearity means the stiffness matrix will change with deformation.
Thanks for your reply.

[hugtalbot]

Hi @10043816beau

Then, yes, the stiffness matrix does indeed change with deformation.

Just in case you did not notice it : our annual event is coming soon SOFA Week 2024. Regarding your recent questions, it would make sense to meet there and discuss further your projects!

Cheers

[SustechShenCong]

Thank you for your reminding !