3 Strategies for Modeling an Electrical Connector
Nicolas Grisé, Dassault Systemes

Introduction
In this article, we will describe 3 modeling options for an electrical connector belonging to a wire harness using the CATIA V5 Electrical tools. The choice of option depends on criteria such as the required fidelity of modeling, precision of weight calculation, part list generation, harness manufacturing, size of dataset, wire extremities and others.

We will explore the 3 options through a basic wire harness example. The harness consists of 2 single insert circular connectors connected by a bundle segment. The bundle segment represents a collection of 3 wires routed to pins in either connector. For each option, we will see the connector modeling details and the relationships between the routed wires and the connectors.

Note that the connector and naming convention used in this example is intentionally simplified to emphasize the intent of this article.

Once again, the choice of modeling option is based on how much value each option brings vs. the extra cost of increasing modeling fidelity.

All the results models in this article were authored using the following CATIA V5 workbenches:

• Electrical Part Design
• Electrical Assembly Design
• Electrical Harness Installation
• Electrical Harness Assembly
• Electrical Wire Routing

Figure 1: Basic wire harness

Figure 2: Wiring schematic

Option 1 – One Termination per connector. Each wire extremity terminates at the connector’s termination

The connector is modeled using one termination. This means that any wires routed to the connector will have the same destination i.e.: Termination 1.

Figure 3: Connector with 1 Termination

By selecting the routed wire and interrogating the related objects, the designer can validate that the wire extremities are connected to their respective connectors.

Figure 4: Extremities of wire 1

Figure 5: Extremities of wire 2

Figure 6: Extremities of wire 3

Option 2 – Many terminations per connector, each corresponding to a contact crimped in a cavity. Each wire extremity terminates at one of the connector’s termination

The connector is modeled using many terminations. This means that wires routed to the connector can each be assigned their own extremity simulating an individual contact, thus providing more precise wiring information for both design validation and harness manufacturing.

Figure 7: Connector with 3 Terminations

By selecting the routed wire and interrogating the related objects, the designer can validate that the wire extremities are connected to their respective connector pins.

Figure 8: Extremities of wire 1

Figure 9: Extremities of wire 2

Figure 10: Extremities of wire 3

Option 3 – Full connector assembly (many parts), including contacts crimped in cavities, each wire terminates at one of the connector’s cavities.

The connector is modeled using many cavities. This means that wires routed to the connector can each be assigned their own extremity. In this case, the wire is routed to a cavity which is, in return, electrically and mechanically connected to a contact (see Figure 12). This highly detailed approach has all the advantages of option 2 and allows the representation of all the parts that are included in the electrical harness assembly. The downsides of this approach are the size of the models (which grows very quickly due to the sheer amount of contacts on a harness) and the time required to build and assemble the parts. Assembly time is greatly reduced as CATIA V5 presently provides the user the ability to auto populate the cavities with contact.

Figure 11: Connector with 3 Cavities

Figure 12: Connector assembly (1 connector, 3 contacts)

By selecting the routed wire and interrogating the related objects, the designer can validate that the wire extremities are connected to their respective contact in the one of the connector cavities. It is then possible to fully validate the electrical connections in the electrical harness.

Figure 13: 1st Extremity of wire 1

Figure 14: 2nd Extremity of wire 1

Figure 15: 1st Extremity of wire 2

Figure 16: 2nd Extremity of wire 2

Conclusion We have seen 3 modeling strategies for electrical connectors using the CATIA V5 Electrical Tools. Each electrical modeling application has unique needs that should be carefully analyzed before choosing one or many of the above options. Generally, the more information and knowledge a 3D model contains the more value it has and the more time and effort is spent in creating and managing it

Nicolas Grisé
CATIA V5 Consultant
Dassault Systemes Inc.
(206) 612-2954
nicolas_grise@ds-ca.com

Links in CATIA Part 4: Icons for Contextual Design
Julie Cyrenne, Dassault Systemes

The last two articles presented the import and the context links. You may have noticed that the figures used in the examples showed different icons for part instances. These icons carry a lot of information about the part’s context. This article will explain the meaning of the four icons that can represent a part instance.

Yellow Gear icon

The yellow gear part icon indicates a non-contextual part. The non-contextual part does not carry any import or context links, but may carry other types of link (for e.g. KWE, CCP).

Green Gear icon

The green gear icon represents the definition instance of the contextual part. The contextual part contains at least one import and one context link, and may contain other types of links.

For each part number, there is only one definition instance of the contextual part. In other words, because all instances of the same part reference have the same geometrical definition, there can only be one instance that defines the geometry. All subsequent instances of the same part number are copies of the definition instance and will feature a different icon.

In the example below, the cylinder is a pad defined to extend up to the surface. The instance Cylinder.1 (green gear), which is the definition instance, does in fact extend up to the surface. On the other hand, the instances Cylinder.2 and Cylinder.3 (brown gear) do not extend up to the surface: they are copies of the Cylinder.1 geometry.

Figure 2: Multiple instances of a contextual part

It is possible to change the definition instance of a contextual part. In the contextual menu of the new definition instance, select ‘Components’ and ‘Define Contextual Links’. The new definition instance will feature a green gear and the geometry of all the instances of that part will morph to the new definition instance geometry, as shown in Figure 3 below.

Figure 3: Change of definition instance of a contextual part

Brown Gear icon

The brown gear icon indicates an instance of a contextual part. The instance of the contextual part will carry the same links as the definition instance of the contextual part, which are an import link, a context link and possibly other types of links.

As illustrated in the example above, all instances of the contextual part other than the definition instance are brown gear instances. These instances do not drive the geometrical definition of the part.

The brown gear can also represent the definition part opened outside its context assembly.

White Gear icon

The white gear icon indicates an instance of the definition contextual part. That instance will carry the same links as the definition contextual part, which are an import link, a context link and possibly other types of links.

The white gear icon indicates a definition instance of the contextual part (green gear) whose context assembly has been inserted in another assembly. Any instance of the definition of the contextual part (brown gear) will always be represented in brown, regardless of the assembly it is opened in. There may be multiple white gear representations of the part.

Figure 4: Instance of the definition instance of the contextual part

Conclusion
The CATPart instance icon carries a lot of information on the part’s context. In light of this, it may be very informative to re-read the articles 2 and 3 of this series (http://www.coe.org/newsnet/Apr05/tips.cfm#1, http://www.coe.org/newsnet/Jun05/tips.cfm#1).

The next article will cover the MML link.

Julie Cyrenne
Dassault Systemes