Modelling of Shear Localisation in Geomaterials

  • Lee, Jun-Seok (Member, Korea Highspeed Rail Construction Authority) ;
  • Pan (Professor, Department of Civil Engineering. University of Wales Swansea, U.K., Professor, Department of Civil Engineering, McMaster University, Canada)
  • 발행 : 1997.06.01

초록

본 연구에서는 암반의 국부파괴 현상을 현실적으로 모형 화하기 위하여 혼합체기법을 적용한 새로운 유한요소를 제안하였다. 이를 위하여 각 유한요소의 적분점에서 재료의 안정성을 검토하고 필요시 국부파괴 요소와 인접한 암반 물성을 이용한 혼합체 물성을 도출하였으며 국부파괴 후의 재료 거동을 추적하였다. 제시한 모형을 사용하면 변형율 연화 모형을 사용하더라도 유한요소망의 객관성을 유지할 수 있으며 국부파괴 이후 재료의 거동을 현실적으로 모형화 할 수 있다. 또한 유한요소 갯수가 비교적 작더라도 수치해석 결과와 실험 결과가 잘 일치하고 있음을 알 수 있다.

In this paper, an enhanced finite element model based on homogenisation technique is proposed to capture the localized failure mode of the intact rock masses. For this, bifurcation analysis at the element level is performed and, once the bifurcation is detected, equivalent material properties of the shear band and neighbouring intact rock are used to trace the post -peak behaviour of the material. It is demonstrated that mesh sensitivity of the strain softening model is overcome and progressive failure mode of rock specimen can be simulated relaistically. Furthermore, the numerical results show that the crack propagation and final failure mode can be captured with relatively coarse meshes and compares well with the experimental data available.

키워드

참고문헌

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