Learning Forum

[karthikeyan.m]

Hello Everyone,

During non-linear simulation, I often facing this convergence issue because of MPC184 element.

Force convergence, Displacement Convergence and Moment Convergence are satisfied. But MPC184 constrain condition are not satisfied.

Can anyone please explain why it is not satisfied and what is the condition to satisfy?

Note: Hyper Elastic materials are not used in my simulation. Also no. of Equilibrium iteration used as 50.

[karthikeyan.m]

Hello Everyone Can anyone please help me to resolve this?

[Erik Kostson]

Hi

There is something going on with the joint elements as per log - have a look and see if you can avoid them perhaps.
This message is often due to overconstraint.

So for this check: any region (edge/face) that is shared by joint and other boundary conditions.

If there is nothing obvious then the best thing is to:
removing the joints and reintroducing them one-by-one until the LAG MULT violation occurs is about the only way to be absolutely certain of the problematic connection. Newton-Raphson residuals might also indicate if there are any joints that are over constrained and causing force imbalance.

All the best

Erik

[karthikeyan.m]

Thanks for the clarification