Variational Bounds for the Equivalent Spring Constants for Bonded Repairs

Abstract

Variational bounds, both upper and lower, are found for the equivalent spring constant of a double-strap joint which represents a sub-element of bonded repairs to cracked structure. Conservative estimates of the equivalent spring constant, needed for accurate design, are obtained from variational analyses of the joint. Estimates from various analytical models of varying level of approximation were obtained. Simpler expressions for the spring constant resulted from relaxing certain assumptions, however, the theoretical guarantee of a true upper or lower bound was lost Spring constant estimates were compared with finite element model results and so the fidelity of the variational bounds, specially for the simplified analyses, could be established. An improved formula is proposed for use in design procedures in RAAF C5033.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1998
Accession Number
ADA360611

Entities

People

  • L. R. Rose
  • Peter Chalkley

Organizations

  • Defence Science and Technology Group

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Aircraft Equipment
  • Aircrafts
  • Airframes
  • Composite Materials
  • Continuum Mechanics
  • Differential Equations
  • Engineering
  • Engineers
  • Equations
  • Laminates
  • Materials
  • Materials Science
  • Mathematics
  • Mechanics
  • Modulus Of Elasticity
  • Stresses

Readers

  • Calculus or Mathematical Analysis
  • Structural Dynamics.
  • Structural Health Monitoring of Composite Structures.