Composite Beam Analysis Linear Analysis of Naturally Curved and Twisted Anisotropic Beams

Abstract

The aim of this report is to present a consistent theory for the deformation of a naturally curved and twisted anisotropic beam. The proposed formulation naturally extends the classical Saint-Venant approach to the case of curved and twisted anisotropic beams. The mathematical model developed under the assumption of span-wise uniform cross-section, curvature and twist, can take into account any kind of elastic coupling due to the material properties and the curved geometry. The consistency of the math-model presented and its generality about the cross sectional shape, make it a useful tool even in a preliminary design optimization context such as, for example, the aeroelastic tailoring of helicopter rotor blades. The advantage of the present procedure is that it only requires a two-dimensional discretization: thus, very detailed analyses can be performed and interlaminar stresses between laminae can be evaluated. Such analyses would be extremely time consuming if performed with standard finite element codes: that prevents their recursive use as for example when optimizing a beam design. Moreover, as a byproduct of the proposed formulation, one obtains the constitutive law of the cross-section in terms of stress resultant and moment and their conjugate strain measures. This constitutive law takes into account any kind of elastic couplings, e.g. torsion-tension, tension-shear, bending-shear, and constitutes a fundamental input in aeroelastic analyses of helicopter blades. Four simple examples are given in order to show the principal features of the method.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1992
Accession Number
ADA252652

Entities

People

  • Gian L. Ghiringhelli
  • Marco Borri
  • Teodoro Merlini

Organizations

  • Polytechnic University of Milan

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Axial Loads
  • Composite Materials
  • Computer Programs
  • Computers
  • Constitutive Equations
  • Differential Equations
  • Elastic Properties
  • Finite Element Analysis
  • Geometry
  • Helicopter Rotors
  • Helicopters
  • Laminates
  • Mechanics
  • Modulus Of Elasticity
  • Operating Systems
  • Three Dimensional
  • Two Dimensional

Readers

  • Computational Modeling and Simulation
  • Mathematical Modeling and Probability Theory.
  • Structural Dynamics.