본 논문에서는 폭발에 의해 생기는 파편의 움직임을 입자계의 내부력을 고려하여 모델링하였다. 입자계의 내부력을 고려하는 이유는 폭발 전후에 입자계 전체의 운동량이 보존되어야 하기 때문이다. 파편의 개수가 수천 개 이상일 경우에는 내부력을 고려하지 않고 난수만을 사용해도 통계적으로 충분히 운동량을 보존시킬 수 있지만 수십 개 이하일 경우에는 통계적으로 더 이상 운동량 보존의 법칙을 만족시킬 수 없다. 이 문제를 해결하기 위하여 입자계의 내부력을 고려한 알고리즘을 제시한다. 이 알고리즘을 사용하면 폭발 후 파편의 개수가 아무리 적어도 운동량 보존 법칙을 만족하게 되어 보다 자연스러운 폭발 장면을 재현할 수 있다.

In response to the increase in international terrorism threats and demands for terrorism prevention and response activities, the Act on Counter-Terrorism for the Protection of Citizens and Public Security was enacted in 2016, and the need for research to strengthen protection against explosive threats was raised. In the same manner, the Design Basis Threats, which become the standard for the design and evaluation of physical protection systems for nuclear facilities, have been developed and it includes explosive threats. However, the regulatory standards for physical barriers against explosive threats are still not established. Therefore, it is first required to set up a performance database of physical barriers subject to blast loading in order to prepare the regulatory standards. In this study, the pressure with the trinitrotoluene (TNT) charge weights of 0.5-2 kg as a function of time was calculated using Ansys Autodyn software by assuming that the TNT is used for malicious purposes and is attached to a reinforced concrete (RC) corridor wall. The shape of the corridor was the 3×3×6 m cuboid with a rectangular hole of 1.78×1.78×6 m. The RC walls, which make up the corridor, contained the reinforcing bars with a spacing of 0.229 m and a diameter of 0.036 m. The spherical charge of a TNT was placed 0.2 m away from a RC wall in the middle of the corridor. To measure the reflected pressure after the internal explosion with a TNT, three pressure gauges were installed on the three sides of the RC walls in the middle of the corridor, respectively. The results showed that the peak reflected pressure on a RC wall with the standoff distance of 0.2 m was about ten times higher than the opposite RC wall with the standoff distance of 1.58 m in the same condition of TNT charge weight. Thus, it was verified that blast loads are highly affected by standoff distance. It seems that preventing the explosive detonation close to a physical barrier is strategically important to maintain the integrity of the physical barrier.