Design Methodology for Scarf Repairs to Composite Structures

Abstract

Scarf repairs are the preferred method of repairing thick composite structures, especially when externally bonded patches can no longer meet the stiffness, strength, and flushness requirements. Present designs of scarf repairs are based on two-dimensional analyses of scarf joints, assuming a uniform stress distribution along the scarf. This report presents an improve design methodology for designing scarf repairs to composite laminates. With the aid of elastic-plastic analyses, a critical assessment of the current design methods has been carried out, with major emphasis being placed on the stress/ strain concentration along the bondline. It is proposed to replace the shear stress criterion with the maximum strain criterion. Comparison with experimental results confirmed that the new approach provides an improved first-order prediction of repair efficiency of scarf repairs.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2006
Accession Number
ADA460738

Entities

People

  • A. Gunnion
  • C. H. Wang

Organizations

  • Defence Science and Technology Group

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Adhesives
  • Aircrafts
  • Composite Materials
  • Failure Mode And Effect Analysis
  • Finite Element Analysis
  • Fracture (Mechanics)
  • Laminates
  • Materials
  • Materials Testing
  • Mechanical Properties
  • Mechanics
  • Shear Stresses
  • Stress Concentration
  • Stress Strain Relations
  • Stresses
  • Three Dimensional
  • Two Dimensional

Readers

  • Facility/Structural Engineering.
  • Life Cycle Cost Analysis
  • Reinforced Composite Materials