Product Overview:

In this session, you’ll model an underwater explosion impacting a cylindrical submarine hull. The key learning objectives include:

• Designing geometries for solid and hull components using revolutions in Abaqus.
• Implementing the Johnson-Cook material model for the hull and defining the acoustic properties for the water domain.
• Properly setting interactions and boundary conditions to simulate the effects of an explosion.
• Analyzing results to visualize damage and evaluate pressure and strain metrics.

This tutorial focuses on the simulation of an underwater explosion shock impacting a cylindrical aluminum shell interacting with soil using Abaqus software. In the model, water is treated as a 3D solid with acoustic properties. The aluminum shell is represented as a three-dimensional shell structure, while the soil is modeled as a solid part.

Naval warfare has become increasingly vital in modern military operations. Since World War II, extensive research has been conducted on underwater explosions (UNDEX), particularly regarding non-contact blasts occurring near the target during precision strikes. The destructive power of such explosions is influenced by several factors, including the distance from the explosion source, the surrounding environment, target dimensions, and material characteristics. In near-field explosions, targets are impacted by the initiation process, detonation products, and shock waves. As the distance from the blast center increases, the effects of detonation products and shock wave energy lessen. Conversely, in far-field explosions, the primary concern is shock wave propagation and the damage effects it induces, as the initiation process becomes less significant. The shock wave’s behavior is heavily dependent on the medium through which it propagates, affecting how the energy is transferred.

In this simulation, water is modeled using acoustic medium properties. For aluminum, an elastic-plastic model with the Johnson-Cook damage criterion is applied. Soil behavior is captured with an elastic material model incorporating Mohr-Coulomb plasticity. The dynamic explicit step is ideal for this analysis. Perfect contact conditions are assumed between the water and soil as well as the water and aluminum shell. The incident wave model (UNDEX method) is used to simulate pressure transfer through the water medium. Proper boundary conditions and mesh configurations are applied to the model.

Upon completion of the simulation, various results such as stress, strain, damage, pore pressure, wave propagation, and soil displacement are available.