periodic boundary

Module: solid

Category: surfaceinteraction

Type string: "periodic boundary"

Parameters

Name	Description	Default	Units
laugon	Enforcement method	0	[]
tolerance	tolerance	0	[]
penalty	penalty	0	[]
two_pass	two_pass	false	[]
offset	offset	{0,0,0}	[]
minaug	minaug	0	[]

Description

The periodic boundary interface enforces the constraint that maintains the relative displacement between two surfaces.

The constraint is enforced using the augmented Lagrangian method, which is controlled by the following parameters.

• laugon : Enables or disables augmented Lagrangian. When disabled, a penalty method is enforced.
• penalty : the penalty factor
• tolerance : the convergence tolerance used for the augmentations.
• minaug : the minimum number of augmentations.

In addition, the following parameters can be specified.

• offset : adds an additional offset to the relative displacement. By attaching a loadcontroller to this parameter, the relative distance can be increased or decreased over time.

• two_pass : when enabled, the constraint is enforced twice and for the second pass the primary and secondary surfaces are swapped.