o3seespy.constraints

class o3seespy.command.constraints.ConstraintsBase

Bases: OpenSeesObject

op_base_type = 'constraints'

class o3seespy.command.constraints.Lagrange(osi, alpha_s=1.0, alpha_m=1.0)

Bases: ConstraintsBase

The Lagrange Constraints Class

This command is used to construct a LagrangeMultiplier constraint handler, which enforces the constraints by introducing Lagrange multiplies to the system of equation. The following is the command to construct a plain constraint handler:

Initial method for Lagrange

Parameters

• osi (o3seespy.OpenSeesInstance) –

• alpha_s (float, optional) – factor on single points.

• alpha_m (float, optional) – factor on multi-points.

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.constraints.Lagrange(osi, alpha_m=1.0)

op_type = 'Lagrange'

class o3seespy.command.constraints.Penalty(osi, alpha_s=1.0, alpha_m=1.0)

Bases: ConstraintsBase

The Penalty Constraints Class

This command is used to construct a Penalty constraint handler, which enforces the constraints using the penalty method. The following is the command to construct a penalty constraint handler:

Initial method for Penalty

Parameters

• osi (o3seespy.OpenSeesInstance) –

• alpha_s (float, optional) – factor on single points.

• alpha_m (float, optional) – factor on multi-points.

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.constraints.Penalty(osi, alpha_m=1.0)

op_type = 'Penalty'

class o3seespy.command.constraints.Plain(osi)

Bases: ConstraintsBase

The Plain Constraints Class

This command is used to construct a Plain constraint handler. A plain constraint handler can only enforce homogeneous single point constraints (fix command) and multi-point constraints constructed where the constraint matrix is equal to the identity (equalDOF command). The following is the command to construct a plain constraint handler:.. note::As mentioned, this constraint handler can only enforce homogeneous single point constraints (fix command) and multi-pont constraints where the constraint matrix is equal to the identity (equalDOF command).

Initial method for Plain

Parameters

osi (o3seespy.OpenSeesInstance) –

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.constraints.Plain(osi)

op_type = 'Plain'

class o3seespy.command.constraints.Transformation(osi)

Bases: ConstraintsBase

The Transformation Constraints Class

This command is used to construct a transformation constraint handler, which enforces the constraints using the transformation method. The following is the command to construct a transformation constraint handler.. note::* The single-point constraints when using the transformation method are done directly. The matrix equation is not manipulated to enforce them, rather the trial displacements are set directly at the nodes at the start of each analysis step.* Great care must be taken when multiple constraints are being enforced as the transformation method does not follow constraints:#. If a node is fixed, constrain it with the fix command and not equalDOF or other type of constraint.#. If multiple nodes are constrained, make sure that the retained node is not constrained in any other constraint.And remember if a node is constrained to multiple nodes in your model it probably means you have messed up.

Initial method for Transformation

Parameters

osi (o3seespy.OpenSeesInstance) –

Examples

>>> import o3seespy as o3
>>> osi = o3.OpenSeesInstance(ndm=2)
>>> o3.constraints.Transformation(osi)

op_type = 'Transformation'