Evaluation of Tearing Instability by Means of Recrystallization-Etch Technique (Comparison of Fracture Toughness Between Through Crack Specimens and Part-Through Crack Specimens)

Kunio Onisawa, Tetsuo Shoji, Hideaki Takahashi, Kotoji Ando

Research output: Contribution to journalArticlepeer-review

Abstract

Tearing instability crack growth in low alloy steels was evaluated in a regime of elastic plastic fracture mechanics by use of recrystallization-etch technique. Specimen geometries used here were standard compact and 3pt bend specimen, and 4pt bend type specimen having a part-through surface crack. In order to produce high compliance for a testing machine, disc springs were used where the compliance changes from lkN/mm to 5kN/mm. After the fracture experiments the crack tip strain energy dissipation rate d WP/da (WP : crack tip strain energy absorbed within the intense strain region, a : tearing crack extension) was determined by the recrystallization-etch technique. It is shown that the value of Tw (tearing modulus based on Wp) is constant before and after an onset of tearing instability. In the surface crack specimen, three dimensional profile of the intense strain region along the crack front was observed. This experimental results indicate that the Tw criterion is applicable to the crack extension from the surface flaw, although a singular extension behavior of the intense strain region was observed only near the specimen surface.

Original languageEnglish
Pages (from-to)514-517
Number of pages4
JournalTransactions of the Japan Society of Mechanical Engineers Series A
Volume51
Issue number462
DOIs
Publication statusPublished - 1985 Jan 1

Keywords

  • Fracture
  • Intense Strain Region
  • Recrystallization-Etch Technique
  • Resistance Curve
  • Surface Crack
  • Tearing Instability

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Evaluation of Tearing Instability by Means of Recrystallization-Etch Technique (Comparison of Fracture Toughness Between Through Crack Specimens and Part-Through Crack Specimens)'. Together they form a unique fingerprint.

Cite this