Modal Analysis Using the Singular Value Decomposition and Rational Fraction Polynomials

Abstract

This report documents the computer codes developed at the Penn State Applied Research Laboratory to extract modal information from experimental vibration measurements. It includes discussions of the numerical techniques used in the analysis, formats for the input files, output from the computer codes, and interpretation of the results. The programs are designed for experimental data sets with multiple drive and response points and have proven effective even for systems with numerous closely-spaced resonance frequencies and relatively high noise levels. For the final stage of the analysis, a graphical interface has been developed to simplify the process of eliminating misidentified modes and refining the predictions for the resonance frequencies, loss factors, and mode shapes. An example problem of a pipe with a bend is used to illustrate the required input and the expected results. Measurements of multiple input-multiple output data for experimental modal analysis can also be useful for computing quantities relevant to statistical energy analysis, and thus calculations for power injection and radiation loss factors are also documented.

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Document Details

Document Type
Technical Report
Publication Date
Apr 06, 2017
Accession Number
AD1035206

Entities

People

  • J. B. Fahnline
  • M. R. Shepherd
  • R. L. Campbell
  • S. A. Hambric

Tags

DTIC Thesaurus Topics

  • Algorithms
  • Computations
  • Computer Programs
  • Computers
  • Data Acquisition
  • Data Sets
  • Experimental Data
  • Fourier Series
  • Frequency
  • Graphical User Interface
  • Instructions
  • Measurement
  • Modal Analysis
  • Multiple Input Multiple Output
  • Pipe Bends
  • Resonant Frequency
  • Transfer Functions

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Computational Modeling and Simulation
  • Theoretical Analysis.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster