Demonstration of component mode synthesis using Lanczos coordinates

Technical Report · Fri May 29 04:00:00 EDT 1987

OSTI ID:6593280

Bumpus, S E; Lu, S C

The concept of component mode synthesis has been introduced, explained, and surveyed in the literature since its first appearance. In this report we review the particular method of component mode synthesis that Flasher (1986) has formulated for the special case of two components, with the more general n-component case being understood as a straightforward extension. Our formulation assumes the use of Lanczos coordinates as reducing vectors and explicitly retains ''attachment modes'' that are used in earlier formulations. We derive the recursive algorithm that generates Lanczos coordinates and quickly review mode superposition. We present an example of component mode synthesis that employs Lanczos coordinates and ''attachment modes'' and that uses a cantilevered 0.6- and 0.4-unit-long beam to synthesis a fixed-fixed 1.0-unit-long beam. Eigenvalue results are accurate for the lower six of nine computed eigenmodes. The eigenvectors show accurate and fairly consistent shapes for all computed eigenvectors. We present simulation and frequency response calculations derived from the synthesis results; we found these to be mostly accurate (as expected) in the lower modes. We conclude with a brief outline of future work. 31 refs., 50 figs., 3 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6593280
• Report Number(s): UCID-20885; ON: DE87010310
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
990230* -- Mathematics & Mathematical Models-- (1987-1989)
ALGORITHMS
DATA
EIGENFREQUENCY
EIGENVALUES
INFORMATION
MATHEMATICAL LOGIC
MATRICES
NUMERICAL DATA
NUMERICAL SOLUTION
THEORETICAL DATA