The Use of Small, Pre-Cracked Bend Specimens for Quality Control Purposes.

Abstract

The difficulties involved in using valid ASTM K sub (Ic) specimens for quality control purposes are described. It is shown from tests on steels and titanium alloys that values of K sub (Ic) can be obtained at lower cost from small specimens. If fracture initiation occurs before general yield, K sub (Ic) can be determined from the load required to cause crack extension. If fracture occurs after general yield, K sub (Ic) can be determined from the critical plane strain crack tip opening displacement or from the notch root contraction. The effect of a steeply rising plane strain R-curve can be corrected by using a newly developed R-extrapolation technique. Simplified versions of the methods involved are described whereby small specimens can be used to determine whether a material satisfies specifications for quality control. These simplified versions require little or no calculation for quality control-testing once master nomographs have been drawn up. (Author)

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1973
Accession Number
AD0773596

Entities

People

  • Alan S. Tetelman
  • Isaac Roman
  • John N. Robinson

Organizations

  • University of California, Los Angeles

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Alloys
  • Crack Tips
  • Cracks
  • Displacement
  • Extrapolation
  • Materials
  • Nomographs
  • Quality Control
  • Specifications
  • Titanium
  • Titanium Alloys

Readers

  • Materials Science (Mechanical Engineering).
  • Systems Analysis and Design