Explosives and Blasting (화약ㆍ발파)

Korean Society of Explosives and Blasting Engineering (대한화약발파공학회)
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Development and Application of an Explosion Modeling Technique Using PFC

PFC3D에서의 폭원모델링 기법의 개발 및 적용

  • Published : 2004.12.01
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Abstract

An explosion modeling technique was developed by using the spherical discrete element code, PFC3D, which can be used to model the dynamic stress wave propagation phenomenon. The modeling technique is simply based on an idea that the explosion pressure should be applied to a PFC3D particle assembly not in the form of an external force (body force), but in the form of a contact force (surface force). According to this concept, the explosion pressure is applied to the wall particles by the scheme of radius expansion/contraction of inner-hole particles. The output wall force is compared to the input hole pressure in every time step, and a correction routine is activated to control the radius multiplier of the inner-hole particles. A comparative blast simulation far a cement mortar block of $80\times90\times80mm$ was conducted by using the conventional explosion modeling method and the new one. The results of the simulation are presented in a qualitative fashion.

본 연구에서는 PFC3D를 사용한 폭원모델링 기법을 제안하고, 제안된 기법을 시멘트 모르타르와 같은 연약재료의 발파에 적용하여 그 적용성을 시험해 보았다. PFC3D는 개별요소법(DEM)을 기반으로 하고 있어 응력파의 전파와 재료의 동적 파괴현상을 모사하는데 적합한 코드로 분류된다. 폭원모델링 과정에서는 공내입자들의 반경을 팽창/수축시키는 기법을 통해 공벽입자들에 접촉력의 형태로 폭발압력을 부여하는 방법을 사용하였으며, 입력하중에 따라 공벽에서 유발되는 접촉력을 계산단계마다 측정 및 보정함으로써 폭발압력의 크기를 제어할 수 있도록 하였다. 시멘트 모르타르 블록의 발파모델링 과정에서는 기존의 외력을 이용하는 방법과 본 연구에서 제안하고 있는 접촉력을 이용하는 기법을 각기 적용함으로써 연약재료의 파괴과정을 정성적으로 비교하여 보았다. 해석결과, 제안된 폭원모델링 기법을 적용한다면 암석이나 콘크리트와 같은 공학재료들이 발파과정에서 보이는 파괴거동을 수치적으로 보다 유사하게 모사 할 수 있을 것으로 판단된다.

Keywords

References

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