A High-Sensitivity Potential-Drop Technique for Fatigue Crack Growth Measurements,

Abstract

This report describes the design features of a highly sensitive and accurate system for monitoring the growth of fatigue cracks in laboratory specimens of various geometries. The system is based on the potential-drop method which utilizes the electrical resistance changes associated with fatigue crack growth through the specimen cross-section to detect crack length increments of a few micrometers. The technique is suitable for automation, and tests may be completed with a minimum amount of operator interference. A computer-based data-processing method is described, and the performance of the system in measuring both absolute crack length and crack growth rate is evaluated.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1979
Accession Number
ADA088278

Entities

People

  • Graham Clark

Organizations

  • Defence Science and Technology Group

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Computer Programs
  • Computers
  • Crack Tips
  • Data Processing
  • Electrical Resistance
  • Fracture (Mechanics)
  • Geometry
  • Laboratory Procedures
  • Materials
  • Materials Testing
  • Measurement
  • Mechanics
  • Micrometers
  • Monitoring
  • Resistance
  • Security
  • Two Dimensional

Readers

  • Structural Health Monitoring of Composite Structures.
  • Systems Analysis and Design