About Connection Properties

When you want to use the connection properties of the Generative Assembly Structural Analysis product, you first need to define a connection that the connection property will reference.

The connections can be created in different ways:

in a product context:

Assembly Constraints in the Assembly Design workbench
Welding Joints in the Automotive Body in White Fastening workbench
Joint Connections in the the Ship Structure Detail Design workbench (Manual Connection command)

Analysis Connections created before V5R12

The former Analysis Connections are still maintained but:

You cannot create them any longer.

You cannot select them as Connection Properties support any longer.
It is strongly recommended to migrate the Analysis Connections created before V5R12.
To do this, refer to Checking the Model.

in an analysis context:
- Analysis Connections in the Generative Structural Analysis workbench (from V5R12)

Why you will use Connections of the Analysis Workbench?

In some cases, constraints are not sufficient to modelize connections from an Analysis viewpoint:

In order to support properties, users often need to define too many constraints using the Assembly Design workbench, leading to over-constrained models that cannot be updated.
It is impossible to define constraints that are not positioning constraints but connection constraints.
It is impossible to select several geometries to define connections in a product context.
It is impossible to select a mechanical feature to define connections in a product context.

In order to meet these different needs, a new Analysis Connection toolbar was added to the Generative Assembly Structural Analysis product of the Generative Structural Analysis workbench.
This toolbar lets you create all these connections dedicated to analysis modeling.

What Type of Hypotheses are Used for Analysis?

You will find here below three types of hypotheses used when working in Analysis workbench.

Small displacement (translation and rotation)
Small strain
Linear constitutive law: linear elasticity

For static case solutions, one can say that:

If there is no contact feature (either virtual or real), no pressure fitting property and no bolt tightening (being virtual or not) feature, then the problem is linear, that is to say, the displacement is a linear function of the load.
In other cases, the problem is non linear, that is to say, the displacement is a non linear function of the load.

What Type of Property For What Type of Connection?

Welding Connections Properties

Spot Welding Connection Property:
- Point Analysis Connection defined in the Generative Structural Analysis workbench (from V5R12)
- Point Analysis Connection within one Part defined in the Generative Structural Analysis workbench (from V5R12)
- Joint Body containing at least a (point) Joint Element and defined in the Body in White Fastener workbench

Seam Welding Connection Property:
- Line Analysis Connection defined in the Generative Structural Analysis workbench (from V5R12)
- Line Analysis Connection within one Part defined in the Generative Structural Analysis workbench (from V5R12)
- Joint Body containing at least a (line) Joint Element and defined in the Body in White Fastener workbench
Surface Welding Connection Property:
- Surface Analysis Connection defined in the Generative Structural Analysis workbench
- Surface Analysis Connection within one Part defined in the Generative Structural Analysis workbench

Other Connection Properties

When you define a connection property, you can select as support:

General Analysis Connection of the Generative Structural Analysis workbench (from V5R12)
Assembly Constraints (Contact Constraint, Coincidence Constraint or Offset Constraint) of the Assembly Design workbench

General Analysis Connection (from V5R12)

`Connection Properties`	Point / Point	Point / Lines*	Point / Faces*	Lines* / Lines*	Lines* / Faces*	Faces* / Faces*
`Slider`
`Contact`
`Fastened`
`Fastened Spring`
`Pressure Fitting`
`Bolt Tightening`
`Rigid`				**	**	**
`Smooth`				**	**	**
`Virtual Rigid Bolt Tightening`
`Virtual Spring Bolt Tightening`
`User-Defined`
* You can multi-select: Lines or 1D mechanical features (example: polylines) Faces or 2D/3D mechanical features (example: extrudes, faces of a pad). ** with optional handler point: the selection of a general analysis connection with a handler point is forbidden for all the other combinations (the pointer indicates what you can select or not).

Assembly Constraints

By default, you can select any assembly constraints as Connection Property support.

Former General Analysis Connections and Face Face Analysis Connections (before V5R12)

You cannot select these connections as Connection Properties support any longer.
It is strongly recommended to migrate the Analysis Connections created before V5R12.
To do this, refer to Checking the Model.

Precisions and Restrictions

Here you will find precisions and restrictions for certain connection properties.

Slider: Slider Connection Property

The slider direction is defined according to the geometry on which the joins are landed.

If you select a former Face Face Analysis Connection (before V5R12) as support, the slider directions are automatically parallel or coaxial.

Contact: Contact Connection Property, User-Defined Distant Connection Property (if you select Contact as Start or End option).
It will be possible to select connections connecting:
- 3D body
- 2D body as support of the contact connection properties with the condition that none of the contact join element generated is flat.
  The connection property fails if the distance between the two connected surfaces is null at one location of the connection.

Pressure Fitting: Pressure Fitting Connection Property

Can be generated only on a geometry belonging to a 3D body.

The fitting direction is defined according to the geometry on which the joins are landed.

If you select a former Face Face Analysis Connection (created before V5R12) as support, the slider directions are automatically parallel or coaxial.

Bolt: Bolt Tightening Connection Property, Virtual Bolt Tightening Connection Property, Virtual Spring Bolt Tightening Connection Property, User-Defined Distant Connection Property (if you select Bolt as Middle option)
- On each side of the assembly, multi-selection of geometry is available.
  In this case, if a geometry has a revolution axis, the other geometries (belonging to the same side of the assembly) must have a revolution axis that must be the same.
- Moreover, if the two sides have a revolution axis (tightening direction), this axis must be the same.
- You can define a bolt connection property (and also virtual bolt tightening, virtual spring bolt tightening and user-defined connection properties) even if the connection is defined between two points.
User-Defined: User-Defined Distant Connection Property
- Refer to Contact.
- Refer to Bolt.
- If you select Beam-Spring-Beam as Middle option, you cannot release degrees of freedom. For all other beam combinations in the middle of a user-defined connection property (for example: Beam, Beam-Spring, Bolt-Beam, Spring-Beam-Spring...), you can release degrees of freedom (only available if the ELFINI Structural Analysis (EST) product is installed).
Face Face Connection Properties:
- Under a certain tolerance, you cannot mesh a face face connection properties.
  This tolerance is a ratio between the distance from the point to the element and the size of the element.
Some Face Face and Distant Connection Properties are authorized in the assembled analysis if you apply them to a general analysis connection built with groups as support.
To know which connection property you can apply to a general analysis connection with groups as support, refer to About Analysis Assembly.