Description: The iterative solver can now achieve better convergence for models that include dense linear constraint equations (such as multi-point constraints, surface-based tie constraints, kinematic couplings, etc.) that eliminate a large number of slave degrees of freedom per master degree of freedom and/or eliminate some slave degrees of freedom in favor of a large number of master degrees of freedom.

Previously in Abaqus 6.10, dense linear constraints would often lead to non-convergence of the iterative solver. In the current release, the iterative solver has a new treatment for dense linear constraints to better achieve convergence.

If a model contains a large amount of dense constraints, performance may be reduced. See “Iterative linear equation solver,” Section 6.1.5, for more details.