Survey on Experimental and Numerical Approaches to Model Underwater Explosions

Abstract

The ability of predicting material failure is essential for adequate structural dimensioning in every mechanical design. For ships, and particularly for military vessels, the challenge of optimizing the toughness-to-weight ratio at the highest possible value is essential to provide agile structures that can safely withstand external forces. Exploring the case of underwater explosions, the present paper summarizes some of the fundamental mathematical relations for foreseeing the behavior of naval panels to such solicitation. A broad state-of-the-art survey links the mechanical stress-strain response of materials and the influence of local reinforcements in flexural and lateral-torsional buckling to the hydrodynamic relations that govern the propagation of pressure waves prevenient from blasts. Numerical simulation approaches used in computational modeling of underwater explosions are reviewed, focusing on Eulerian and Lagrangian fluid descriptions, Johnson-Cook and Gurson constitutive materials for naval panels, and the solving methods FEM (Finite Element Method), FVM (Finite Volume Method), BEM (Boundary Element Method), and SPH (Smooth Particle Hydrodynamics). The confrontation of experimental tests for evaluating different hull materials and constructions with formulae and virtual reproduction practices allow a wide perception of the subject from different yet interrelated points of view.

Pressure Wave Caused by Trinitrotoluene (TNT) Underwater Explosion—Short Review

“…The article attempts to collect most of the descriptions of various researchers and implement them for CAE (Computer Aided Engineering) purposes. A similar approach has been proposed in [30]. Table 1 presents formulas necessary to calculate shock waves caused by underwater TNT explosion pressure values and their waveforms.…”

Dynamic Response of Drill Floor Considering Propagation of Blast Pressure Subsequent to Blowout

“…There are several approaches to analyze explosion such as the Smoothed Partial Hydrodynamic (SPH) Method, Boundary Element Method (BEM) and Finite Volume Method (FVM). These methodologies are reviewed, and a validity check has been carried out [20]. This study utilizes FLACS which adopts FVM, since it is widely used and accepted for explosion analysis in offshore projects and petroleum industries.…”

Simulation of the Behavior of a Ship Hull under Grounding: Effect of Applied Element Size on Structural Crashworthiness

“…The numerical model of the bottom structure defined in ANSYS LS-DYNA [26] with reference to the shell elements was used in this study. The element formulation utilized the fully integrated version of the Belytschko-Tsay [27,28] to suppress hourglass energy during the application of accidental loading to the ship structures. In the analysis, steel was defined while using a plastic-kinematic model (see Table 6) with kinematic hardening being applied to the structure.…”