Adhesive Bonded Doubler for H-3 Helicopter Blade Spar

Abstract

The effectiveness and reliability of an adhesive bonded boubler in the elimination of crack formation and growth due to stress concentration in a metallic substructure is demonstrated. Quantitative design information to enable optimization of the doubler is developed and the methods for the field application of doublers to the H-3 spar are described. A preliminary mechanical and thermal stress analysis has shown that a boron/epoxy laminate should provide the lightest weight, thinnest, and most reliable double compared to any other available material, except perhaps beryllium sheet material. The mechanical and thermal loads induced in the doubler and the adhesive bond under the most severe conditions, operating at -65 F, are 44,500 psi compression and 1050 psi shear respectively.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1971
Accession Number
AD0882745

Entities

People

  • Theodore J. Reinhart Jr.

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Bonded Joints
  • Composite Materials
  • Epoxy Composites
  • Epoxy Laminates
  • Finite Element Analysis
  • Graphite Epoxy Composites
  • Helicopter Rotors
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Materials Testing
  • Mechanical Working
  • Steady State
  • Stress Analysis

Readers

  • Aerospace Engineering
  • Metallurgy
  • Structural Health Monitoring of Composite Structures.