In this thesis, the suppression of jet formation in a shaped charge warhead through the infiltration of hyperelastic materials into the warhead was researched. Three types of rubber materials, which is incompressible and two types of compressible polyurethane materials were selected as hyperelastic materials, and the infiltration effect and jet formation inhibition performance of hyperelastic materials on a shaped charge warhead were investigated through numerical analysis and experiments. In this study, LS-DYNA, a commercial finite element analysis code, was used for numerical analysis. In the numerical analysis, it was predicted that the three types of rubber materials would not have a jet formation inhibition effect due to the insufficient infiltration depth into the warhead, and this was confirmed by the flash X-ray experiment. While, the two polyurethane low hardness materials were found to be highly effective in infiltration into the warhead interior and suppressing jet formation through both the warhead flight collision test and the flash X-ray experiment. Numerical simulations of warhead collision considering the brittle fracture and viscoelastic behavior of the polyurethane low hardness materials were in good agreement with the flight test results. In the jet formation analysis using the 2D Arbitrary Lagrangian Eulerian (ALE) technique, the effect of infiltration depth of the polyurethane low hardness material on jet formation inhibition was investigated and compared with the results of flash X-ray experiments.
본 논문에서는 탄 내부로의 초탄성 재료의 침투를 통한 성형작약탄의 제트 형성 억제에 대해 연구하였다. 초탄성 재료로는 비압축성인 3종 고무재료와 압축성인 2종의 polyurethane 재료를 선택하였으며 수치해석과 실험을 통해 성형작약탄에 대한 초탄성 재료의 침투효과와 제트형성억제 효과를 조사하였다. 수치해석을 위해 상용 유한요소해석 코드인 LS-DYNA를 사용하였다. 수치해석에서 3종 고무재료의 경우는 탄 내부로의 침투깊이가 작아서 제트 형성 방해 효과가 없을 것으로 예측되었으며 섬광 X선 실험을 통해 이를 확인하였다. 반면 2종 polyurethane 재료는 탄 비행충돌실험과 섬광 X선 실험에서 탄 내부로의 침투효과 및 제트형성억제 효과가 매우 큰 것으로 나타났다. Polyurethane 재료에 대한 점탄성 거동이 고려된 탄 충돌 수치해석은 비행충돌실험 결과와 잘 일치하였으며, 2D ALE 기법을 이용한 제트 형성 해석에서 polyurethane 재료의 침투깊이에 따른 제트형성 방해효과를 조사하였으며 이를 섬광 X선 실험결과와 비교하였다.
