HD78731: ANALYSIS (GSA) / SINGULARITY IS DETECTED WHEN STIFFNESS IS INCR EASED.

APAR status

• Closed as Permanent restriction.

Error description

• ANALYSIS (GSA) / SINGULARITY IS DETECTED
  WHEN STIFFNESS IS INCREASED.
  .
  Scenario.
  .
  1. Open Part2.CATAnalysis. If Translation Stiffness
  1 in SmoothSpringVirtualPart.1 was changed,
  Translation Stiffness 2 and 3,in
  SmoothSpringVirtualPart.1 and all Translation
  Stiffness in SmoothSpringVirtualPart.2,3 and 4 are
  followed.
  2. Double Click on Smooth Spring Virtual Part.1
  3. Change the Translation Stiffness 1 to
  5e+010N_m then click OK button.
  4. Click Compute icon.  Computation is completed
  without any error.
  5. Double Click on Smooth Spring Virtual Part.1
  6. Change the Translation Stiffness 1 to
  5e+020N_m then click OK button.
  7. Click Compute icon.  Error message is
  displayed.
  This is a problem.
  .
  Expected result:
  Computation should be completed without any
  error.
  .
  

Local fix

Problem summary

• ANALYSIS (GSA) / SINGULARITY IS DETECTED WHEN STIFFNESS IS INCR
  EASED.
  ANALYSIS (GSA) / SINGULARITY IS DETECTED
  WHEN STIFFNESS IS INCREASED.
  .
  Scenario.
  .
  1. Open Part2.CATAnalysis. If Translation Stiffness
  1 in SmoothSpringVirtualPart.1 was changed,
  Translation Stiffness 2 and 3,in
  SmoothSpringVirtualPart.1 and all Translation
  Stiffness in SmoothSpringVirtualPart.2,3 and 4 are
  followed.
  2. Double Click on Smooth Spring Virtual Part.1
  3. Change the Translation Stiffness 1 to
  5e+010N_m then click OK button.
  4. Click Compute icon.  Computation is completed
  without any error.
  5. Double Click on Smooth Spring Virtual Part.1
  6. Change the Translation Stiffness 1 to
  5e+020N_m then click OK button.
  7. Click Compute icon.  Error message is
  displayed.
  This is a problem.
  .
  Expected result:
  Computation should be completed without any
  error.
  .
  

Problem conclusion

• THIS PROBLEM IS PERMANENT RESTRICTION IN
  CATIA
  Incident Diagnosis
  Singularity is detected when stiffness is increased.
  Restriction Explanation
  The stiffness introduces in the spring leads to an ill
  condition stiffness matrix. Thus causing singualarity
  error.
  However user has to note that the stiffness value is
  too big in this case.
  By-Pass
  If the stiffness is too big, then use rigid element.
  Note : When Translation Stiffness 1 is changed to
  5e+040N_m and compute is done, please check
  the translational displacement magnitude image.
  This shows value as zero, as element is highly stiff.
  .
  

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:

Fix information

Applicable component levels