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Modify Body - Mass Properties

By default, Adams View calculates the mass and inertia for a rigid body part based on the part’s geometry and material type. The geometry defines the volume and the material type defines the density. The default material type for rigid bodies is steel.

You can change the material type used to calculate mass and inertia or simply specify the density of the part. If you do not want Adams View to calculate mass and inertia using a part’s geometry, material type, or density, you can enter your own mass and moments of inertia.

It is possible to assign zero mass to a part whose six Degrees of freedom you constrain with respect to parts that do have mass. You should not assign a part zero mass, however. Any part that has zero mass and translational degrees of freedom can causes simulation failure (since a = F/m). Therefore, we recommend that you assign finite masses and inertias to all parts. In addition, a part without mass cannot have mass moments of inertia.

Learn about Methods for Calculating Mass Properties.

For the option:	Do the following:
Define Mass By	Set to: ■Material Type ■Geometry and Density ■User Input
If you selected Material Type, the following options appears:
Material Type	Enter the type of material for the rigid body. Adams View displays the material’s composition below the text box. Adams View uses the density associated with the material type and volume of the geometry of the part to calculate the part’s mass and inertia. Learn about Standard Material Properties. Tips on Entering Object Names in Text Boxes.
Show calculated inertia	Select to view the mass-inertia tensor matrix that Adams View calculates.
If you selected Geometry and Density, the following options appears:
Density	Enter the density of the part. Adams View uses the part’s density and the volume of the geometry to calculate its mass and inertia.
Show calculated inertia	Select to view the mass-inertia tensor matrix that Adams View calculates.
If you selected User Input, the following options appear:
Mass	Enter the mass of the part.
Moments of inertia	Enter the mass moments of inertia. Learn About Entering Mass Moments of Inertia.
Center of Mass Marker	Enter the marker that is to be used to define the center-of-mass (CM) for the part.
Off-Diagonal Terms	Select to enter the cross-products of inertia (Ixy, Ixz, and Iyz). Clear to enter just the principal mass moments of inertia (Ixx, Iyy, Izz).
Inertia Reference Marker	Specify the marker that defines the axes for the inertia properties. If you do not enter an inertia marker, Adams View uses the part CM marker for inertia properties.
	Add any comments about the variable to help you manage and identify it. You can enter any alphanumeric characters. The comments appear in the Information window when you select to display information about the request, in the Adams View Log file, and in a command or dataset file when you export your model to these types of files.