\\

Coupled [constraints|kb:Constraint] and [restraints|kb:Constraint] may be modeled using {new-tab-link:http://www.csiberkeley.com/}CSI{new-tab-link} Software. While coupling often works well, [numerical problems|kb:Numerical problems] may sometimes occur. To successfully model coupling, it is recommended that users connect multiple joints with a constraint, and then use stiff (but not too stiff) elements to connect pairs of joints to the assembly of constraints.

{related-incident:no=23987|comment=Fixed link connected to fixed restraints results in zero reactions in moving load analysis. See 5/29/2010 action.}


{hidden-content}
h2. Is there an example of how constraint coupling may cause numerical instability?

*Answer:* {open-question}
{hidden-content}