A Novel System for Miniature and Micro Specimen Fatigue and Fracture Testing.

Abstract

A microspecimen testing system has been developed to conduct real-time fatigue and fracture measurement on specimens less than 1 mm thick. Principal components include an interferometric-based crack opening displacement (COD) gage, a piezoelectric actuator, a resistive load cell, and an integrally machined testing cell and loading fixtures. Software has been developed to rapidly analyze interference signals and provide close-loop cyclic control. The principal system limitation is that the maximum real-time cyclic testing frequency is only 1/4 Hz for the relatively large specimens tested. System measurement resolution based on the load, COD, and load-line displacement is adequate for B = 1 mm SE(B) specimens, and illustrates the capability to test much smaller specimens. Initial system testing has indicated the following: the effects of planar rigid body motion have been simply discriminated from actual COD, compliance estimates based on these COD readings are accurate for a/W= 0.5, and system stability appears to be reasonable.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1997
Accession Number
ADA328855

Entities

People

  • G. P. Mercier
  • R. L. Tregoning

Organizations

  • Naval Surface Warfare Center Carderock Division

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Actuators
  • Calibration
  • Cells
  • Data Acquisition
  • Detectors
  • Displacement
  • Electronic Components
  • Frequency
  • Lasers
  • Light Sources
  • Load Cells
  • Materials
  • Measurement
  • Mechanical Properties
  • Mechanics
  • Physics Laboratories

Readers

  • Aerospace Test and Evaluation
  • Control Systems Engineering.
  • Materials Science (Mechanical Engineering).