ANALYTICAL AND EXPERIMENTAL DETERMINATION OF THE NATURAL FREQUENCIES AND MODE SHAPES OF SKEW PLATES.

Abstract

The accuracies of equivalent mass matrices for a triangular and rectangular element based on linearly varying static displacements were tested in natural frequency and mode shapes calculations for a simply supported square plate. Accuracies for the fundamental frequency of a nine degree-of-freedom plate were found within 10%. A lumped mass matrix resulted in an accuracy within 0.5%. The lumped mass and triangular element mass matrix were extended to frequency calculations for 60, 45, and 30 degree simply supported skew plates, each with aspect ratios of 1, 1/2, and 1/3. Results were disappointing when compared to experimental frequencies. Too many inaccuracies existed in the experimental and analytical method. Photographs were taken of mode shapes. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1965
Accession Number
AD0615281

Entities

People

  • Keete Lockett Hester

Organizations

  • Air Force Institute of Technology

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Aspect Ratio
  • Displacement
  • Frequency
  • Photographs
  • Photography
  • Resonant Frequency

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Control Systems Engineering.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering