Vibration Analysis of Clustered Launch Vehicles
Abstract
The Saturn I vehicle represents a complex ensemble of nine beams joined together. A first vibration analysis based on an equivalent single beam did not agree satisfactorily with the test results of the full scale test vehicle. Comparison of analysis and test results rather dictates that the coupling effects of the nine single beam vibrations can not be neglected. Hence the analysis developed in this paper is based on a model consisting of nine clustered beams. However, the complexity of the system calls for many simplifying assumptions. basic idea of the analysis consists in coupling of the single beam vibrations such that the connections of the beams will be preserved. The method applied to the uncoupled single beams is the well known transfer matrix method. The mentioned coupling of the single beam vibrations leads to a linear homogeneous system of compatibility equations which must be solved during each transfer. Realization of the boundary conditions leads to a frequency curve indicating the coupled frequencies of the system. Finally the coupled mode shapes can be determined. The analysis is programmed on IBM-709-4. Because it consists of simple matrix operations the computer time is short. The results of an analysis of the Saturn I vehicle compare well with test results.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1965
- Accession Number
- ADA399823
Entities
People
- Everette E. Beam
- Rudolf F. Glaser
Organizations
- National Aeronautics and Space Administration