Usually the navigation property name does not exactly match its corresponding Smart 3D relationship name. To determine the specific Smart 3D relationship name, look in the Description annotation.
For example, to determine the meaning of the Components navigation property on the EquipmentEntity Entity, view the EquipmentEntity/Components annotation (shown below) that shows it uses the Smart 3D HasEqpComponents relation:
<Annotations Target="Com.Ingr.Smart3d.V1.EquipmentEntity/Components">
<Annotation Term="Org.OData.Core.V1.Description" String="Navigation property from the EquipmentEntity object to the collection of EquipmentComponent using the HasEqpComponents relation" />
</Annotations>
Annotations can be accessed at <ServiceRoot>/Annotations/$metadata.