PARAM, UCORD

Bulk Data Entry Specifies the coordinate system in which the mass moment of inertia is output. It also can be used to control the point about which the mass moment of inertia is calculated.

Parameter Values Description
UCORD <CID>

Integer ≥ -1

 PARAM,UCORD controls the calculation of mass related properties like mass moment of inertia and center of gravity. It controls both output from PARAM,GRDPNT and OUTPUT,MASSPROP. It also affects the values of these properties when they are used in the solution (both for analysis and optimization). Therefore, for optimization with center of gravity and moment of inertia responses, they will be affected by PARAM,UCORD.
-1 (Default)
The mass moment of inertia is calculated about the center of gravity and is output in the basic coordinate system.
0
The mass moment of inertia is calculated about the origin of the basic coordinate system. The output values are expressed in the basic coordinate system.
> 0
The center of gravity coordinates are expressed in the coordinate system CID. The mass moment of inertia is calculated about the center of gravity and expressed in the coordinate system CID.

Comments

  1. If PARAM, UCORD is not specified, CID = -1, or CID given is not found, all values in PARAM, GRDPNT are calculated relative to the basic coordinate system.
  2. If PARAM,UCORD is not specified, or CID given is not found, the center of gravity is output in the basic coordinate system and the related mass properties are calculated with respect to the center of gravity. This applies for these values which are used in the solution and for OUTPUT,MASSPROP.
  3. If PARAM, GRDPNT is not specified in the input deck, then the center of gravity and moment of inertia are not output regardless of the value of PARAM, UCORD.
  4. The values of PARAM, GRDPNT does not affect the output of Center of Gravity and Mass Moment of Inertia output via OUTPUT, MASSPROP.