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A Study on the Unloading Stiffness of Instrumented Indentation Tests

계장화 압입 시험에서 하중 제거 곡선의 강성률에 관한 고찰

  • 이병섭 (한국원자력연구소 원자력재료기술개발부) ;
  • 이호진 (한국원자력연구소 원자력재료기술개발부) ;
  • 이봉상 (한국원자력연구소 원자력재료기술개발부)
  • Published : 2004.02.01

Abstract

Instrumented indentation tests have been used for estimating material properties. In order to analyze deformation characteristics with various factors, the unloading stiffness should be properly determined from the elastic behavior. The unloading stiffness is generally obtained from the shifted power functions fitting with the experimental unloading data. However, the functions often give rise to a poor representation of actual data, and also the unloading stiffness is governed by unloading condition. In this study, both numerical and experimental conditions to obtain proper unloading stiffness were investigated. The result showed that the amount of unloading ratio and hold time played an important role in fitting the unloading curves. The current efforts can successfully provide the unloading stiffness for indentation material properties.

Keywords

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