MPC
The Lagrange multiplier method can be used to define constraints. Extra storage is required for the so-called auxiliary bordered stiffness matrix. The constraint is satisfied exactly.
Although the MPC object belongs to the Constraint class, it behaves like a Load object. Hence, a
proper Amplitude object is required to be present. If 0 is assigned to [2], a default ramp function will be
assigned automatically.
Users are not expected to assign boundary conditions via MPC constraint or Tie element.