Hi, I am facing buckling convergence issues while using 1D beam elements (B31) in compression. I suppose it is due to the Newton Algorithm which could not handle the stiffness drop past the buckling limit.

A solution : While using only one (simple) Riks (Static, Riks) procedure step, the convergence is reached. However, the model I use need several steps in it and the use of MODELCHANGE Activation feature.

This Activation feature is not available in Riks procedures and a Riks step must be the last in the simulation (I couldn't use several Riks steps in the simulation).

Would you have any idea regarding the solver type I should use instead of the Riks ? Or if the Riks is mandatory, would you know how to solve the last two issues (MODELCHANGE Activation unavailable & several steps required) ?

Thank you in advance for you help and consideration