Computational investigation of the mitigation of an underwater explosion

The protection effects of a mitigation layer in an underwater explosion are investigated here. The explosion shock loads on a mitigated structure are computed by a Mie–Grüneisen mixture model. Validation tests show that the model is efficient for the underwater explosion problem. Then underwater explosion problems with different mitigation layers are simulated here. In these simulations, special attention is paid on the second shock wave, which is induced by the reflection of the main shock wave. From the results, it is found that the shock impedance of the mitigation layer plays an important role. It determines not only the property of second shock loads, but also the occurrence of protection effects of the mitigation layer. After that the protection effects of layer thickness and explosive–structure distance are studied here. It is found that these factors influence the main shock slightly, but have significant influence on the second shock. In addition, the compressible structure can also be protected by the mitigation layer.