Moment-of-Inertia: Radius-of-Gyration, and Point-Mass.

Case 1:

If you enter a Mass but do NOT enter a Radius-of-Gyration or Moment-of-Inertia, the Mass is reduced to a Point Mass.

The position of the mass is at (center-of-Mass: X–axis, center-of-Mass: Y–axis).

CASE 2:

If you enter Moment-of-Inertia, then the equivalent Radius-of-Gyration, is :

Case 3:

If you enter Radius-of-Gyration, then the equivalent Moment-of-Inertia, is:

Parallel Axis Theorem

We use the Parallel Axis Theorem to calculate the Moment-of-Inertia about the Part's instantaneous center-of-rotation.

= distance to the Center-of-Mass from the center-of-rotation.

When you import a SolidWorks document onto a CAD-Line, you can also import the SolidWorks Mass-Properties

Button IMPORT / UPDATE SolidWorks Mass Properties

Note: Before you click button , make sure the active SolidWorks document is on the CAD-Line.

Button Remove SolidWorks Mass Properties

Total Mass Properties:

The Total Mass Properties is for ALL CAD-Lines in one Part.

EXPLICITLY: the Total Mass Properties include, for each Part, ALL of those:

•Mass and Mass-Properties as calculated for ALL Profile/Extrusions in the Part

•User Mass-Properties as defined for ALL CAD-Lines in the Part

•SolidWorks Mass-Properties as defined for ALL CAD-Lines in the Part

NOTES:

Parallel-Axis Theorem

Inertia about Part's Rotational-Axis = Total Inertia about center-of-Mass + Mass × (Distance to Part's Rotational-Axis)2

Relationship between Moment-of-Inertia and Radius of Gyration

Total Inertia (about center-of-Mass) = Total Mass × (Radius-of-Gyration)2

Total Mass of Part =

Mass of all Extrusions + Total mass of other CAD-Lines in the same Part

Total Inertia about the Part's center-of-Gravity =

Inertia of all Extrusions + Total Inertia of other CAD-Lines in the same Part