Mass property definition
 @MASS_PROPERTY_DEFINITION {
 @MASS_PROPERTY_NAME {MassPropName} {
 @TOTAL_MASS {m_{00}}
 @CENTRE_OF_MASS_LOCATION {η_{1}, η_{2}, η_{3}}
 @MOMENTS_OF_INERTIA {ρ_{11}, ρ_{12}, ρ_{13}, ρ_{22}, ρ_{23}, ρ_{33}}
 @WITH_RESPECT_TO_MASS_CENTRE {CenterFlag}
 @COMMENTS {CommentText}
 }
 }
NOTES

This section defined the mass properties of a rigid body mass. m_{00} is the total mass of the body.
Figure 1. Configuration of the rigid body.

The configuration of the rigid body is depicted in fig. 1. Point B is the reference point of the rigid body coordinates η_{1}, η_{2}, and η_{3} of the center of mass are defined in the local coordinate system attached to the corresponding rigid body.

The components of the moment of inertia tensor, ρ_{11}, ρ_{12}, ρ_{13}, ρ_{22}, ρ_{23}, and ρ_{33}, are defined in the local coordinate system. Two reference points are possible for this definition depending on the value of the parameter CenterFlag. (Default value: CenterFlag = NO)

if CenterFlag = NO, the components of the moment of inertia tensor are measured in the local coordinate system, with respect to the origin of the local coordinate system. For this option, ρ_{11}, ρ_{12}, ρ_{13}, ρ_{22}, ρ_{23}, ρ_{33} are the components of tensor ρ^{B}, as defined in eq. 4.

if CenterFlag = YES the moments of inertia are measured in the local coordinate system, with respect to the center of mass of the body. For this option, ρ_{11}, ρ_{12}, ρ_{13}, ρ_{22}, ρ_{23}, ρ_{33} are the components of tensor I^{C}, as defined in this eq. (4).

The relationship between tensors ρ^{B} and ρ^{C} is readily found based on the parallel axis theorem, see eq. (5).

It is possible to attach comments to the definition of the object; these comments have no effect on its definition.