Hello everyone, which method does CalculiX use for distributed coupling, direct elimination method or Lagrange multiplier method? I know Distributed coupling constraints in Abaqus/Standard use the Lagrande multiplier method.
Coupling constraints in CalculiX are of course based on the Abaqus ones but there are some differences due to the way CalculiX handles rotational DOFs. Check the documentation chapter 6.7.3. Kinematic and Distributing Coupling for more details.
CalculiX use direct methods by equation and weighted factors, did Abaqus use modified stiffness in coupling constraints to avoid numerical stability?
reading their documents only apply to contact with rigid body (hard type), it seems CalculiX use the multiplier in Mortar Contact type only.