Constraint handler

class xc.ConstraintHandler

Bases: xc.MovableObject, xc_base.CommandEntity

Constraint handlers enforce the single and multi freedom constraints that exist in the domain by creating the appropriate FE_Element and DOF_Group objects.

class xc.FactorsConstraintHandler

Bases: xc.ConstraintHandler

Base class for penalty and Lagrange constraints handlers.

property alphaMP

Factor applied with multi-freedom constraints.

property alphaSP

Factor applied with single-freedom constraints.

class xc.PenaltyConstraintHandler

Bases: xc.FactorsConstraintHandler

Handle single and multi point constraints by using the penalty method. This is done by, in addition to creating a DOF_Group object for each Node and an FE_Element for each Element in the Domain, creating either a PenaltySFreedom_FE or a PenaltyMP_FE object for each constraint in the Domain. It is these objects that enforce the constraints by modifying the tangent matrix and residual vector.

class xc.LagrangeConstraintHandler

Bases: xc.FactorsConstraintHandler

Handle single and multi point constraints by using the Lagrange multipliers method. This is done by, in addition to creating a DOF_Group object for each Node and an FE_Element for each Element in the Domain, creating a LagrangeDOF_Group object and either a LagrangeSFreedom_FE or a LagrangeMP_FE object for each constraint in the Domain. It is these objects that enforce the constraints by modifying the tangent matrix and residual vector.

class xc.PlainHandler

Bases: xc.ConstraintHandler

Handle homogeneous single point constraints. Create regular FE_Element and DOF_Group objects and enforce the constraints by specifying that degrees-of-freedom which are constrained are not assigned an equation number.

class xc.TransformationConstraintHandler

Bases: xc.ConstraintHandler

Handle single and multi point constraints by using the Lagrange multipliers method. This is done by, in addition to creating a DOF_Group object for each Node and an FE_Element for each Element in the Domain, creating either a TransformationSFreedom_FE or a TransformationMP_FE object for each constraint in the Domain. It is these objects that enforce the constraints by modifying the tangent matrix and residual vector.