Determination of Fixed-Base Natural Frequencies of a Composite Structures or Substructures: Experiment and Application

摘要

A generalized method, reported in NRL Report 7300, for determining the fixed-base natural frequencies of an in situ or laboratory mechanical structure or substructure is tested by experiments. The test structure was composed of a simple steel beam on three supports which were mounted on flexible members of a trusslike frame. The fixed-base natural frequencies of the lowest two modes of the test beam were determined by the aforementioned semianalytical method. Theoretical calculations and a standard resonance test were also performed for comparison. Results comfirmed the applicability and usefulness of the developed method, as predicted by the theoretical analysis. (Author)