.VehicleInterfaces.UsersGuide.ModelRotatingParts

Information

Within VehicleInterfaces rather than limiting our-selves to modelling rotating components as a simple 1D rotation we have built in the flexibility to model rotating components as MultiBody systems. This has been possible through the development of a new connector called FlangeWithBearing. This is a hierarchical connector that contains a 1D rotational connector and a conditional MultiBody connector. The use of the MultiBody connector is controlled by a parameter in the connector. This enables the FlangeWithBearing connector to model rotational effects as a purely 1D system or it can correctly include MultiBody effects.

Where this connector is used in an interface definition the parameter includeBearingConnector is linked to a parameter at the model level so that the model developer can easily activate this connector if required. These parameters are declared as protected parameters so that they are only available to the model developer as they create the subsystem model and cannot be changed when the model is used.

The use of the bearing connectors needs to carefully considered to avoid inadvertently creating mechanical loops in the model. The following example guidelines for the engine and transmission subsystems should help highlight the issues so that the model developer can determine when it is appropriate to use the bearing connectors. For the engine and transmission subsystem models:

1. When they are modelled as a pure 1D rotational system then no bearing connectors are required.
2. When they are modelled as a 1D rotational system with reactions on to a MultiBody system then no bearing connectors are required.
3. When they are being modelled as a MultiBody system but they are rigidly connected together then the bearing frame between the engine and transmission should not be included. In this case the transmissionMount connector should support the MultiBody elements of the transmission. The rest of the model then needs to be considered before deciding whether to include the bear-ing between the transmission and driveline or be-tween the engine and accessories subsystems.
4. When they are being modelled as a MultiBody system but they are not rigidly connected together then the bearing frame between the engine and transmission will be required to support the intermediate drive shaft.