Nondestructive Detection of Structural Damage Uniquely Associated with Fatigue

Abstract

The program was directed at the development of reliable nondestructive testing and inspection methods to locate and assess fatigue damage in Air Force aircraft structures. The primary nondestructive test approach is the application of exoelectron emission to the detection of fatigue damage. Initially, a series of controlled fatigue tests were conducted in an ultrahigh vacuum chamber to fully characterize the surface state of the specimen prior to, during, and after fatigue measurement. Next, a series of fatigue tests were conducted in air on specimens of different shapes with and without discontinuities under various loading and environmental conditions, in order to develop a practical technique for applying exoelectron emission and surface potential difference measurements to assess fatigue damage as well as to predict final failure sites. A porototype system design for the automatic scanning and exoelectron emission testing of aircraft-type structures was developed.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1974
Accession Number
ADA005357

Entities

People

  • D. O. Thompson
  • J. F. Moore
  • S. A. Hoenig
  • S. Tsang

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aircrafts
  • Alloys
  • Aluminum Alloys
  • Chemistry
  • Detectors
  • Fatigue Tests (Mechanics)
  • Geometry
  • Materials
  • Materials Laboratories
  • Measurement
  • Mechanics
  • Optical Properties
  • Recording Systems
  • Surface Properties
  • Surface Roughness
  • Test And Evaluation
  • Test Methods

Readers

  • Structural Health Monitoring of Composite Structures.