Constraint equation scaling

The constraint equations of the problem are scaled to improve the conditioning of the differential/algebraic governing equations. The scaling factor, sca, used to normalize the constraint equations of the problem can be specified in two manners using the parameters defined in the step control parameter data section.

  • Select a constant value, sca, for the constraint scaling factor. This simple approach works fine in most cases.
  • Select values for average stiffness and average mass terms of the structure, denoted kave and mave, respectively. The scaling factor is then computed at each step size as

    sca = kave + mave/Δt2.

    This approach is preferred when very small time steps are expected to occur during the simulation, such as in contact problems, for instance.

(Default value: sca = kave = 1.0 10+06, mave = 0.0)