model.massProp()

Compute mass properties and add mass contributions.

Syntax

model.massProp().create(<tag>,"MassProperties");

model.massProp(<tag>).selection();

model.massProp(<tag>).set(<pname>,<expr>);

 

model.massProp(<tag>).create(<mctag>, "MassContributions");

model.massProp(<tag>).feature(<mctag>).selection()

model.massProp(<tag>).feature(<mctag>).set(<pname>,<expr>);

Description

Creating Mass Properties and Providing Geometry Source Selections

model.massProp().create(<tag>,“MassProperties”) creates a mass properties object that computes variables for mass properties such as total mass and the center of mass.

model.massProp(<tag>).selection().set(...) defines a local selection that assigns the mass properties to geometric entities that act as sources. For a complete list of methods available under selection(), see model.selection().

Specifying Density and Mass Properties

You can specify the density to be taken from a physics. For example,

model.massProp(<tag>).set("densitySource", "fromSpecifiedPhysics")

model.massProp(<tag>).feature("mc1").set("physics", "solid");

takes the density from the Solid Mechanics interface solid.

You can also specify a user-defined density. For example, to specify the density to be 1107 kg/m3, use

model.massProp(<tag>).set("densitySource", "userDefined");

model.massProp(<tag>).set("expr","1107[kg/m^3]");

To create variables for the center of mass and to not create variables for the moment of inertia:

model.massProp(<tag>).set("createCenterOfMass","on");

model.massProp(<tag>).set("createMomentOfInertia","off");

Adding a Mass Contribution

You can add mass contributions from other parts of the geometry (an adjacent boundary, for example) by creating a mass contribution:

model.massProp(<tag>).create("mc1","MassContributions");

model.massProp(<tag>).feature("mc1").set("expr", "3");

For the mass contributions, you can specify source selections and define the density in the same way as for the mass properties.

Properties and Variables for massProp

The massProp feature accepts the following properties:

Table 2-61: massProp properties

name	Value	Default	Description
createCenterOfMass	on|off	on	Create center of mass variables.
createMass	on|off	on	Create mass variable.
createMassContribution	on|off	on	Add a mass contribution.
createMomentOfInertia	on|off	on	Create moment of inertia variables.
createPrincipalInertia	on|off	on	Create principal moment of inertia variables.
createVolume	on|off	on	Create volume variable.
densitySource	fromSpecifiedPhysics|userDefined	userDefined	Source for the density values.
expr	string		User-defined density expression.
includeLowerPh	on|off	on	Include adjacent entities of lower dimension for density values taken from physics.
integrationFrame	frame	Material	Integration frame for user-defined density.
intorder	4	Positive integer	Integration order.
outputFrame	frame	Material	Integration frame for output variables.

The created variables for different mass properties have the following default names:

•	mass1.mass and mass1.volume for the mass and volume, respectively.

•	mass1.CMX, and so on, for the coordinates of the center of mass.

•	mass1.IXY, and so on, for the components of the moment of inertia.

•	mass1.Ip1, and so on, for the moment of inertia principal values.

•	mass1.Ip1X, and so on, for the moment of inertia principal directions.