ORTHOGONALLY STIFFENED PLATES

Abstract

An experimental method is presented for the determination of the effective stiffness moduli of an actually stiffened structure. Rectangular portions of plate containing a sufficient number of stiffners were subjected to pure bending and twisting couples distributed along their edges. Stiffness factors in the 2 principal orthogonal directions for both grooved- and rod- stiffened plates differed by as much as 50%. The bending and twisting tests gave reliable elastic constants for calculating flexural behavior of the orthogonally stiffened plates under various loads. Vibration experiments appeared to give good confirmation of the value of the proposed method. The assumption that the boundaries of the plates are simply supported was verified by the agreement between the theoretical and observed frequencies of an unstiffened plate. The product of mass density and thickness of plate occurring in the derived equations can be determined directly as mass/unit area of plate by weighing a typical section of the plate and dividing by its area.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1953
Accession Number
AD0017400

Entities

People

  • W. H. Hoppmann

Organizations

  • Johns Hopkins University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aeronautics
  • Air Force
  • Applied Mechanics
  • Boundaries
  • Differential Equations
  • Engineering
  • Equations
  • Frequency
  • Materials
  • Materials Laboratories
  • Measuring Instruments
  • Mechanical Engineering
  • Mechanics
  • Military Research
  • Navy
  • New York
  • Stiffness

Readers

  • Structural Dynamics.