Mass Contributions
In the Definitions toolbar, click to add a Mass Contributions () node, which you can use to add contributions to the mass used for computing the mass properties in the parent Mass Properties node. Under Definitions, you can also right-click Mass Properties to add this feature.
The contributions can come from a connected boundary, for example. The Settings window for a Mass Contribution node includes the following sections:
Source Selection
The source selection defines the source for the mass contribution to the mass properties — the part of the geometry where you want to add mass contributions.
From the Geometric entity level list, select Domain (the default), Boundary, Edge (3D only), or Point. Select Manual or All domains (the default), All boundaries, All edges, or All points from the Selection list. If Manual is selected, select geometric entities in the Graphics window.
Density
In this section you define the source of the density values used for computing some of the mass properties using the Density source list:
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Choose User defined (the default), to define a value or expression for the density in the Density expression field (SI unit: kg/m3). For example, material.rho, which is a variable for the density from the materials in the model. From the Density input frame list, specify the frame to which the input density refers: Material (the default in 3D), Mesh, Geometry, or Spatial. Note that the actual coordinate names — typically (x, y, z) or (X, Y, Z) in 3D — are displayed for each frame, indicating which frames differ from each other in the current model.
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Choose From physics interface to take the density from the active physics interface in the geometry. If there are two or more physics interfaces that provide a density in the same domain, the first contributions are then overwritten by the last one (but the density is then typically the same in those physics interfaces). The Include adjacent entities of lower dimension check box is selected by default to include the density also on adjacent boundaries, edges, and points.
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Choose From specified physics interface to take the density from a physics interface that you choose from the Physics list. The Include adjacent entities of lower dimension check box is selected by default to include the density also on adjacent boundaries, edges, and points.