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Evaluation of Indentation Fracture Toughens in Brittle Materials Based on FEA Solutions

유한요소해에 기초한 취성재료의 압입파괴인성평가

  • Hyun, Hong Chul (Dept. of Mechanical Engineering, Sogang Univ.) ;
  • Lee, Jin Heang (Reactor Mechanical Engineering Division, Korea Atomic Energy Research Institute) ;
  • Felix, Rickhey (Dept. of Mechanical Engineering, Sogang Univ.) ;
  • Lee, Hyungyil (Dept. of Mechanical Engineering, Sogang Univ.)
  • Received : 2013.06.06
  • Accepted : 2013.09.16
  • Published : 2013.12.01

Abstract

In this study, we proposed an indentation evaluation method for fracture toughness using cohesive finite element simulations. First, we examined the effect of material properties (yield strain, Poisson's ratio, and elastic modulus) on crack size during Vickers indentation and then generated a regression formula that explains the relations among fracture toughness, indentation load, and crack size. We also proposed another indentation formula for fracture toughness evaluation using the contact size a and E/H (H: hardness). Finally, we examined the relation between the crack size and the indenter shapes. Based on this, we can generate from the formula obtained using the Vickers indenter a formula for an indenter of different shapes. Using the proposed method, fracture toughness is directly estimated from indentation data.

Keywords

Fracture toughness;Indentation cracking test;Cohesive zone model;Indenter geometry;Number of cracks;FEA

Acknowledgement

Supported by : 한국연구재단

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