When selecting the Manual option on the Concentrated Mass form, the following sections are available:
- Coordinate System: This allows you to select a coordinate system used for Inertia and Offset definitions.
- Selected Entities: Selection box for you to select vertex points.
- Mass: Input box where you can define the mass value.
- Display Options: Allows you to edit the display options of the concentrated mass.
- Size: Changes the size of the concentrated mass.
- Color: Allows you to pick the color of the concentrated mass.
- Add To Analysis: This checkbox automatically puts this concentrated mass under Analysis\Idealizations.
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Inertia:
- You can define the mass moments of inertia here.
- The form of the inertia matrix about its center of gravity is taken as:
where:
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Offset:
- You can offset the mass defined at vertices from their center of gravity (CG).
- If a coordinate system is selected, then X1, X2, X3 are defined by a local Cartesian system similar to the method in which displacement coordinate systems are defined.