part create point_mass mass_properties
Creates the mass properties on an existing point mass.
The mass properties of a point_mass include the mass and the center-of-mass marker. You may assign zero mass to a point_mass whose three degrees of motion you constrain with respect to bodies that do have mass. However, due to the number of changes that you may make to the dataset in the course of defining a model, the probability of a later change requiring that the point mass have mass is high. Therefore, we recommend that you assign finite (although insignificant) masses and inertias to point masses that you would otherwise assign zero mass properties.
If you specify the mass for a point_mass, you must also specify the center-of-mass marker for the point_mass.
Format:
part create point_mass mass_properties | |
|---|---|
point_mass_name= | existing point_mass |
mass= | mass |
center_of_mass_marker= | existing marker |
density= | density |
material_type= | existing material |
Description:
Parameter | Value Type | Description |
|---|---|---|
point_mass_name | Existing point mass | Specifies the name of the part to create or modify. |
Mass | Mass | Specifies the mass of the point mass. |
center_of_mass_marker | Existing marker | Enter the marker that is to be used to define the center-of-mass (CM) for the part. |
density | Density | Specifies the part density and that the mass properties of the part are to be automatically calculated. |
material_type | Existing material | Specifies the material type of the part and that the mass properties of the part are to be automatically calculated. |
Extended Definition:
1. If the point mass has no mass, Adams View uses the point mass local part reference frame (LPRF) to represent the position of the point mass internally. If the point mass has mass, Adams View uses the position of the center-of-mass marker to represent the translational position of the point mass internally.
The orientation of the point_mass and the center-of-mass marker have no effect on the simulation.
2. If the point mass has mass, Adams View uses the position of the CM marker to represent the translational position of the point mass internally.
3. Adams View uses the part’s density and the volume of the geometry to calculate its mass and inertia.
Standard Material Properties
The following table shows the material properties for the standard material types in Adams View. All material types in Adams View are assumed to be linearly elastic. Adams View automatically calculates the material’s Shear Modulus (G) from the Young’s Modulus (E) and Poisson’s Ratio (ν) according to the equation:
The material: | Young’s Modulus value (Newton/meter2): | Poisson’s Ratio: | Density (kg/meter3): |
|---|---|---|---|
Aluminum | 7.1705E+ 10 | 0.33 | 2740.0 |
Cast iron | 1.0E+11 | 0.211 | 7080.0 |
Steel | 2.07E+11 | 0.29 | 7801.0 |
Stainless steel | 1.9E+11 | 0.305 | 7750.0 |
Magnesium | 4.48E+10 | 0.35 | 1795.0 |
Nickel | 2.07E+11 | 0.291 | 7750.0 |
Glass | 4.62E+10 | 0.245 | 2595.0 |
Brass | 1.06E+11 | 0.324 | 8545.0 |
Copper | 1.19E+11 | 0.326 | 8906.0 |
Lead | 3.65E+10 | 0.425 | 11370 |
Titanium | 1.0204E+11 | 0.3 | 4850.0 |
Tungsten | 3.447E+11 | 0.28 | 19222 |
Wood | 1.1E+10 | 0.33 | 438.0 |
1. When using the Adams View command language and naming entities, you can use the name later to refer to this entity. Adams View does not allow you to have two entities with the same full name, so you must provide a unique name. Normally, entity names are composed of alphabetic, numeric, or '_' (underscore) characters, and start with an alphabetic or '_' character. They may be any length. For more information, see Using Extended Names.
By enclosing the name in double quotes, you can use other printable characters, or start the name with a numeral. If a name contains characters, or starts with a numeral, you must always quote the name when entering it.
Note that you can specify the parentage of an entity (for example, what part "owns" a marker or a geometry element) when you create it by changing the name. If you enter just the entity name, then Adams View assigns the default parent. If you type in the full name, then you can override the default parent. In most cases, when creating an entity, Adams View provides a default name. The default name that Adams View provides specifies the parentage that it has assumed. You can, or course, delete this name and use your own. The form of a full name is:
"...._NAME.GRAND_PARENT_NAME.PARENT_NAME.ENTITY_NAME"
The number of levels used varies from case to case and the parentage must exist before an entity can be assigned to it.