3.2.1.5. Auto Constraint Handler

This command is used to construct an Auto constraint handler.

This handler combines the advantages of both the Transformation and the Penalty methods.

In the current implementation, single-point constraints are handled with the Transformation method, while multi-point constraints are handled with the Penalty method.

The following is the command to construct such a constraint handler:

constraints Auto <-verbose> <-autoPenalty $oom> <-userPenalty $userPenalty>

Argument	Type	Description
-verbose	string	(optional, default = not-defined) If defined, OpenSees will report some debug information.
-autoPenalty $oom	string + float	(optional, default = -autoPenalty defined, oom = 3). With this option, each multi-point constraint will be assigned an automatic penalty value \(\alpha_M=10^{koom + oom}\), where \(koom=round(\log_{10}(K))\) is the approximate order-of-magnitute of the (initial) stiffness matrix at the nodes involved in the multi-point constraint.
-userPenalty $userPenalty	string + float	(optional, default = note-defined). If defined, a uniform penalty parameter \(\alpha_M=userPenalty\) will be used for all multi-point constraints

Example 1

The following example shows how to construct an Auto Method constraint handler with the default settings: automatic penalty values computed for each multi-point constraints

1. Tcl Code

constraints Auto

2. Python Code

constraints('Auto')

Example 2

The following example shows how to construct an Auto Method constraint handler with extra settings to print debug information (-verbose) and to compute penalty values for each constraints as 4 order-of-magnitute larger than the stiffness found on the nodes involved in each multi-point constraint.

1. Tcl Code

constraints Auto -verbose -autoPenalty 4

2. Python Code

constraints('Auto', '-verbose', '-autoPenalty', 4)

Code Developed by: Massimo Petracca at ASDEA Software, Italy.