Table of Contents

Mass Properties

MassPropertiesCoordinateSystem

The origin of the MassPropertiesCoordinateSystem is the centre of mass for the section where the MassPerUnitLength and the MomentOfInertia in the associated property group, MassProperties are defined. The orientation of the MassPropertiesCoordinateSystem is used in conjunction with the RadiusOfGyration to associate the mass contribution along the x-axis and y-axis.

blade-section-mass-system.svg

Figure 1: Mass properties coordinate system.

MassProperties

The MassProperties are defined in the MassPropertiesCoordinateSystem

The MassProperties properties are:

  • MassPerUnitLength: The mass per unit length at this section.
  • MomentOfInertia: The mass moment of inertia per unit length for this section.
  • RadiusOfGyrationRatio: The radius of gyration of mass about \(\bunit{Y_mass}\) divided by the radius of gyration of mass about \(\bunit{X_mass}\).

Example of the properties in JSON format:

"MassProperties": {
    "MassPerUnitLength": 2803.711,
    "MomentOfInertia": 17141.45,
    "RadiusOfGyrationRatio": 1.0
}

The mass properties are applied using the same approach as the StructuralProperties illustrated in the note about NeutralAxisCoordinateSystem orientation. It is, therefore, advisable to consider this when constructing the ReferenceCoordinateSystem and the orientation of the MassPropertiesCoordinateSystem.