Attachments

Attachments offer a means to connect definition-based analyst entities such as systems, analyses, data sets and templates.

An attachment is a local connecting entity within a definition such as a system that helps connect to other entities outside of the system.

While assembling a model with different systems, it is often necessary to connect or refer entities in one system to entities in another system. To retain modularity of the system so that they can be reused in a different context, it is recommended that the connections to external entities be defined via attachments.

In the figure below, system A and system B are two system containing parts. System B has joints that connected parts within the system to parts in system A.
Figure 1.


While the parts in system A can directly be used for defining joints in system B as shown above, this method is not recommended. When system B has many connections that use one or a few entities as reference, those connections have to be resolved individually when the system is reused elsewhere or if the system A is replaced. Instead, system B can have attachments and parts be referred through the attachments as illustrated in image below.
Figure 2.


System B now has 2 attachments, att_1 and att_2. Parts from system A are referred into these attachments and the joints use the attachments instead of the parts. If system A needs replacement, updating attachments for system B would be sufficient to restore any unresolved references within system B.

  • Attachments enable systems to be reusable in same or different model.
  • Any analyst entity type can be passed as an attachment including systems.
  • An attachment can be referred by multiple entities within the system. Changing the attachment reference once, updates all the entity references at once.
  • Once an attachment is defined and resolved, the attachment has the same set of properties as the entity that is passed into. The attachment could also be used in a parametric expression while defining properties of another entity.

Example

The figure below shows a two cylinder engine model. The crankshaft is external to the Piston-Conrod system. To define joints and forces in the Piston-Conrod system, attachments Crank Center, Crank Pin Attachment and CrankShaft Body Attachment are created and resolved to Crankshaft Center (Point), Crank pin (Point) and Crank shaft part that are in the Crankshaft system.
Figure 3.


Attachments are not limited to systems alone. Other definition based entities such as data sets and analysis also support attachments, following the same principle.

Attachment Tags and Attachment Candidates

You can assign a tag to an attachment in a system or other container entity. A tag works with an attachment candidate, which is defined on an entity in another system. Attachment tags and candidates help in automatically resolving attachments without the need for the user to manually select the attachment.

To define an attachment candidate on an entity, open the Property Editor for the entity and click Attachment Candidate in the Notes and Tags section.

You can define an attachment tag in the guide panel of the system or other container entity in the Tag column of the Attachments table.

For example, using the two cylinder engine model, for the Crank Pin point in the Crankshaft system, you can add an the attachment candidate with the value "CrankPin."


In the Piston-Conrod system, you can define a point attachment with a tag value of "CrankPin" and resolve the Point collector to automatically select the point with the matching attachment candidate tag.


Note: An entity can have multiple attachment candidate tags.

More than one entity of a type can have the same candidate tag. All entities that have the same tag are considered possible candidates for an attachment that has the same attachment tag.

Add Attachment

Once the system, dataset or analysis is created or is being edited, the attachments table is displayed in the guide panel.
Figure 4.


  1. Under the Attachments section, for Type, select an entity type to be added as an attachment from the dropdown.
  2. Select whether to create a single attachment or a pair.
    If not checked, only a single entity can be resolved into the attachment. An attachment entity, like most of the analyst entities that are created in Inspire, can be a single entity or a pair entity. Pair entities help in creating models which have symmetric properties. For more information, see Pairs and Symmetric Modeling in Inspire Motion.
  3. Click + to create the attachment.
  4. Change the Name and the Label for the newly added entry in the table.
  5. Activate the collector under the Selection column corresponding to the new row.
  6. Pick the entity the attachment will be resolved to, either from the modeling window or use the Advanced Selection by clicking ....

Edit an Attachment

  1. Select the definition-based entity whose attachments will be edited.
  2. Use one of the following methods to bring up the entity's guide panel.
    • Click on the entity's ribbon icon.
    • In the Property Editor, click on any of the attachments row.
  3. To add a new attachment, follow steps as described in the Add Attachment section.
  4. To edit an existing attachment:
    1. Change the Name and the Label for the attachment in its row.
    2. Activate the collector under the Selection column.
    3. Pick the entity the attachment will be resolved to, either from the modeling window or use the Advanced Selection by clicking ....
  5. To delete the attachment, activate any cell along the attachment name. Click Delete.