This study investigates the effect of weather conditions on the explosive power of warheads detonated in the cavity of the hill soil. A coupled experiment-numerical approach was proposed using the MM-ALE solver of the LS-DYNA code to simulate shock wave propagation in warheads, soil-air interactions, and craters formed by blast loading during sunny and rainy weather. Field blast experiments were employed to validate the numerical models, in which crater depth, diameter, and volume were measured and compared with simulated values. The model provided a relative accuracy, with relative errors in crater volume below 10% for all the cases. Numerical and experimental findings both revealed that the crater volumes produced under saturated conditions were significantly higher, with absolute differences ranging from 1.39 m3 to 2.95 m3 for two warheads compared to those under dry conditions. The application of the mapping technique in numerical simulations is a favorable and robust approach to the assessment of the destructive performance impacting the surrounding medium.
Plain language summary
Why was the study done? Explosions positioned in the ground behave differently depending on soil moisture. This study examined which weather conditions make warheads more or less destructive to adjust the explosive type and charge mass so that a desired target for each condition. What did the researchers do? Simulations were conducted to model the processes of blast phenomenon in a soil cavity. Afterward, field blast tests were carried out in hill soil under sunny and rainy conditions to compare with simulation results. The tests measured crater depth, diameter and volume so direct comparisons with the simulations could be made. What did they find? Craters were larger in wet conditions, with the biggest differences occurring near the soil surface where rainwater had soaked in. At deeper soil levels the crater shapes were quite similar to those formed in dry ground. The validated simulation reproduced the experimental crater volumes with errors below 10%. For the two warhead types tested, craters under wet conditions were larger by about 1.39 to 2.95 m3 compared with that under dry ones. What do the findings mean? The findings show that the developed simulation model can reliably reproduce the behavior of soil explosions under different weather conditions, that leads to reduce real blast tests. Moreover, since wet and dry soils respond differently, achieving the same destructive effect under varying conditions requires adjusting the charge type or mass. Overall, these results provide useful details for our future studies to optimize the warhead design in different conditions.
