Accession Number:

ADA289304

Title:

Analysis of Modal Behavior at Frequency Cross-Over.

Descriptive Note:

Final rept.,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s):

Report Date:

1994-11-28

Pagination or Media Count:

250.0

Abstract:

The existence of the mode crossing condition is detected and analyzed in the Active Control of Space Structures Model 4 ACOSS4. The condition is studied for its contribution to the inability of previous algorithms to successfully optimize the structure and converge to a feasible solution. A new algorithm is developed to detect and correct for mode crossings. The existence of the mode crossing condition is verified in ACOSS4 and found not to have appreciably affected the solution. The structure is then successfully optimized using new analytic methods based on modal expansion. An unrelated error in the optimization algorithm previously used is verified and corrected, thereby equipping the optimization algorithm with a second analytic method for eigenvector differentiation based on Nelsons Method. The second structure is the Control of Flexible Structures COFS. The COFS structure is successfully reproduced and an initial eigenanalysis completed.

Subject Categories:

  • Unmanned Spacecraft
  • Numerical Mathematics
  • Computer Programming and Software

Distribution Statement:

APPROVED FOR PUBLIC RELEASE