Suggested Method for Determining a Complete Set of Micro-Parameters Quantitatively in PFC2D

PFC2D 활용을 위한 정량적 미시변수 결정법

  • 정용훈 (서울대학교 에너지자원신기술연구소) ;
  • 이정인 (서울대학교 공과대학 지구환경시스템공학부)
  • Published : 2006.08.31

Abstract

The discrete element code in 2-D, PFC2D, has been used as a tool to simulate various phenomena in rock mechanics and rock engineering. However, the code has an disadvantage that procedure to determine micro-parameters, namely properties of particles and contacts is repetitive and time-consuming. In this study, we analyzed the effect of micro-parameters(for generation of a contact-bonded model) on macro-properties(that were measured numerically by uniaxial compressive test). Based on the analysis, also, the time-saving and reliable method was suggested to determine a complete set of micro-parameters. In order to verify the suggested method, numerical specimens were generated in PFC2D for 10 different rock types at home and abroad. By the two trials for each specimen, in the result, the Young's modulus, Poisson's ratio and uniaxial compressive strength could be reproduced with being in relative error by about 5% to the values obtained by laboratory tests.

개별요소법을 사용한 수치해석 프로그램인 PFC2D는 암석역학에 많이 사용되고 있다. 그러나 해석 모델을 구성하는 입자와 접촉의 특성을 결정하기 위해서는 시행오차적인 지루한 반복 과정을 거쳐야 한다. 본 연구에서는 해석 모델을 정의하는 미시변수가 일축압축시험으로부터 얻어지는 거시 물성에 미치는 영향을 분석하였다. 또한 분석 결과에 기초하여 간단하고 신뢰할 수 있는 정량적인 미시변수 결정법을 제안하였다. 제안된 미시변수 결정법을 검증하기 위하여 10종류의 암석 시험편을 생성하기 위한 수치 실험을 수행하였다. 그 결과 단 2회의 수치 실험만으로 탄성계수 포아송비 그리고 일축압축강도를 실험실 시험값과의 상대오차 % 내외로 재현할 수 있었다.

Keywords

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