If the part is a deformable planar part that is modeled with generalized plane strain elements, you must create a reference point to indicate the required reference node. For more information, see Creating generalized plane strain sections. For more information on generalized plane strain elements, see Choosing the element's dimensionality.
If the part is a discrete or analytical rigid part, you use the reference point to indicate the rigid body reference point. Constraints or motion that you apply to the reference point are applied to the entire rigid part.
The location of the rigid body reference point affects how you prescribe moments or motion; in addition, the location of the rigid body reference point affects the interpretation of moment reactions. If your model includes a dynamic analysis involving rotations, the rotary inertia specification of a rigid body must be made consistent with the location of its rigid body reference point.
You must refer to a reference point on the assembly when you create a rigid body constraint in the Interaction module. A rigid body constraint constrains the motion of regions of the assembly to the motion of a reference point. You can create and name a set containing the reference point and refer to the set, or you can select the reference point directly from the current viewport. You can also apply loads and boundary conditions to a reference point in the Load module.
In some cases you will want to position the reference point at the center of mass, which you can find using the Query toolset. You can use the Property module to assign mass and rotary inertia section properties to the reference point. The section can also include optional damping data.
You can apply constraints to a reference point; for example, equation, coupling, and display body constraints.
You can use a reference point when you create an assembly-level wire feature in the Assembly module or the Interaction module. A reference point is useful if you want to attach the connector to a point in space. You can create a reference point at the desired location and use a rigid body constraint to attach a part instance to the reference point. When you attach a connector to such a reference point, the connector is effectively attached to the part instance.