Evaluation of dynamic fracture toughness parameters by instrumented Charpy impact test

Kobayashi Toshiro, Yamamoto Isamu, Niinomi Mitsuo

Research output: Contribution to journalArticlepeer-review

80 Citations (Scopus)


This paper presents methods to determine two fracture mechanics parameters using load-deflection curves obtained from instrumented Charpy impact test. Two fracture mechanics parameters are dynamic fracture toughness (Jd) and material tearing modulus (Tmat). Jd is fracture resistance at crack initiation and it is necessary to detect the crack initiation point on the load-deflection curve for measurement of this value. On the other hand, Tmat is a parameter to characterize a stable crack growth and it is necessary to estimate an amount of crack extension. In this study, it is attempted to detect the crack initiation point by calculating the compliance changing rate from a load-deflection curve for the measurement Jd. Next, J-Δa curve is estimated by using a key curve method and Tmat, is determined from the slope of it. In addition, Tmat is evaluated by combining Kaiser's rebound compliance with Paris-Hutchinson's Tapp equation. The above results are compared with the ones of the stop block test (which is a multiple specimen technique), and are discussed with respect to their validity; a rather good agreement is ascertained.

Original languageEnglish
Pages (from-to)773-782
Number of pages10
JournalEngineering Fracture Mechanics
Issue number5
Publication statusPublished - 1986

ASJC Scopus subject areas

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


Dive into the research topics of 'Evaluation of dynamic fracture toughness parameters by instrumented Charpy impact test'. Together they form a unique fingerprint.

Cite this