HC81450: MEASURE INERTIA MOMENT/AXIS GIVES WRONG RESULTS ON A SURFACE IN APPROXIMATIVE MODE.

APAR status

• Closed as program error.

Error description

• The result of measuring  the Moment of Inertia of a flat surface
  about axis is wrong, using the Moment/Axis feature in  the
  Measure Inertia menu.
  .
  SCENARIO FROM SCRATCH
  1  Create a sketch, for instance a RECTANGLE on which the
  Measure inertia is going to be done.
  2  Create a line, which will act as the axis for the inertia
  3  Create a surface out of the RECTANGLE With "Fill" for
  instance. Also reate a Pad from the sketch, with a very small
  thickness, for instance 0.01mm
  4  Click on the Measure Inertia icon
  5  Click to select the surface, created under 3).
  6  In the Measure Inertia dialog box, click the Select axis
  checkbox
  7  Select the axis in the geometry area, created under 2)
  8  Take note of the Mass Moment of Inertia
  9  Repeat steps 5 to 8 for the Pad. Adjust the Surface Density
  so that
     the Mass of the Pad becomes the same as for the surface.
  10 Observe that the Mass Moment of Inertia for the Surface
     and the Pad are different even though they should have been
     equal. Hand calculations shows that the CATIA calculated Mass
     Moment of Inertia of the Pad is correct and for the Surface
  is wrong.
  

Local fix

Problem summary

•  INCIDENT DIAGNOSIS:
  MEASURE INERTIA MOMENT/AXIS GIVES WRONG RESULTS ON A SURFACE
   IN APPRO
   XIMATIVE MODE.
  
   TECHNICAL EXPLANATION FOR THE CORRECTION:
  Correction provided in pds7 on 13/08/2001 ( R7SP3 )
  
  SpaceAnalysis/CATSpaInertia.m/src/CATMeasureCalcVolInertia.c
  pp
  
  Unity problem in inertia measure 2d (matrix in M4 and not in M5)
  

Problem conclusion

• THIS PROBLEM WILL BE FIXED ON
    CATIA VERSION 5 RELEASE 8 GA level.
  NOTE THAT THIS PROBLEM WILL ALSO BE FIXED ON V5R7SP03.
  
   INCIDENT DIAGNOSIS:
  MEASURE INERTIA MOMENT/AXIS GIVES WRONG RESULTS ON A SURFACE
   IN APPRO
   XIMATIVE MODE.
  
   TECHNICAL EXPLANATION FOR THE CORRECTION:
  Correction provided in pds7 on 13/08/2001 ( R7SP3 )
  
  SpaceAnalysis/CATSpaInertia.m/src/CATMeasureCalcVolInertia.c
  pp
  
  Unity problem in inertia meaure 2d (matrice en M4 and not in M5)
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

•    FILE
  

Fix information

• Fixed component name

  CATIA V5 NT_INT

• Fixed component ID

  569151000

Applicable component levels

• R506 PSN

     UP

• R507 PSN SP50703

     UP01/10/15 I 1000