OdbAssembly object

The OdbAssembly object has no constructor; it is created automatically when an Odb object is created. Abaqus creates the rootAssembly member when an Odb object is created.

This page discusses:

Access

import odbAccess
session.odbs[name].rootAssembly

ConnectorOrientation(...)

This method assigns a connector orientation to a connector region.

Required arguments

region

An OdbSet specifying a region.

Optional arguments

localCsys1

An OdbDatumCsys object specifying the first connector node local coordinate system or None, indicating the global coordinate system.

axis1

A SymbolicConstant specifying the axis of a cylindrical or spherical datum coordinate system about which an additional rotation of the first connector node is applied. Possible values are AXIS_1, AXIS_2, and AXIS_3. The default value is AXIS_1.

angle1

A Float specifying the angle of the additional rotation about the first connector node axis. The default value is 0.0.

orient2sameAs1

A Boolean specifying whether the same orientation settings should be used for the second node of the connector. The default value is OFF.

localCsys2

An OdbDatumCsys object specifying the second connector node local coordinate system or None, indicating the global coordinate system.

axis2

A SymbolicConstant specifying the axis of a cylindrical or spherical datum coordinate system about which an additional rotation of the second connector node is applied. Possible values are AXIS_1, AXIS_2, and AXIS_3. The default value is AXIS_1.

angle2

A Float specifying the angle of the additional rotation about the second connector node axis. The default value is 0.0.

Return value

None.

Exceptions

If region is not an element set:

OdbError: Connector orientation assignment requires element set.

SectionAssignment(...)

This method is used to assign a section on an assembly or part. Section assignment on the assembly is limited to the connector elements only.

Required arguments

region

An OdbSet specifying a region.

section

A Section object.

Optional arguments

None.

Return value

None.

Exceptions

If region is not an element set:

OdbError: Section assignment requires element set.

addElements(...)

This method is used to define elements using nodes defined at the OdbAssembly and/or OdbInstance level. For connector elements connected to ground, specify the lone node in the connectivity. The position of the ground node cannot be specified. This is a limitation.

Warning:

Adding elements not in ascending order of their labels may cause Abaqus/Viewer to plot contours incorrectly.

Required arguments

labels

A sequence of Ints specifying the element labels.

connectivity

A sequence of sequences of Ints specifying the nodal connectivity.

instanceNames

A sequence of Strings specifying the instanceNames of each node in the nodal connectivity array. If the node is defined at the assembly level, the instance name should be an empty string

type

A String specifying the element type.

Optional arguments

elementSetName

A String specifying a name for this element set. The default value is the empty string.

sectionCategory

A SectionCategory object for this element set.

Return value

None.

Exceptions

Only certain element types are permitted at the assembly level. e.g., connector elements.

OdbError: Addition of this element type is not permitted at the assembly level

If length of label array does not match connectivity data length:

OdbError: Connectivity array must be provided for all element

addNodes(...)

This method adds nodes to the OdbAssembly object using node labels and coordinates.

Warning:

Adding nodes not in ascending order of their labels may cause Abaqus/Viewer to plot contours incorrectly.

Required arguments

labels

A sequence of Ints specifying the node labels.

coordinates

A sequence of sequences of Floats specifying the nodal coordinates.

Optional arguments

nodeSetName

A String specifying a name for this node set. The default value is None.

Return value

None.

Exceptions

If length of labels does not match length of coordinates:

OdbError: Number of node labels and coordinates does not match

If width of coordinate array does not match assembly dimension:

OdbError: Node location specification does not correspond to part dimensions

RigidBody(...)

This method defines an OdbRigidBody on the assembly.

Required arguments

referenceNode

An OdbSet specifying the reference node assigned to the rigid body.

Optional arguments

position

A symbolic constant specify if the location of the reference node is to be defined by the user. Possible values are INPUT and CENTER_OF_MASS. The default value is INPUT.

isothermal

A Boolean specifying an isothermal rigid body. The default value is OFF. This parameter is used only for a fully coupled thermal stress analysis.

elset

An OdbSet specifying an element set assigned to the rigid body.

pinNodes

An OdbSet specifying pin-type nodes assigned to the rigid body.

tieNodes

An OdbSet specifying tie-type nodes assigned to the rigid body.

analyticSurface

An AnalyticSurface specifying the Analytic Rigid Surface assigned to the rigid body.

Return value

None.

Exceptions

If referenceNode is not a node set:

OdbError: Rigid body definition requires a node set.

Members

The OdbAssembly object can have the following members:

instances

A repository of OdbInstance objects.

nodeSets

A repository of OdbSet objects specifying node sets.

elementSets

A repository of OdbSet objects specifying element sets.

surfaces

A repository of OdbSet objects specifying surfaces.

nodes

An OdbMeshNodeArray object.

elements

An OdbMeshElementArray object.

datumCsyses

A repository of OdbDatumCsys objects.

sectionAssignments

A SectionAssignmentArray object.

rigidBodies

An OdbRigidBodyArray object.

pretensionSections

An OdbPretensionSectionArray object.

connectorOrientations

A ConnectorOrientationArray object.