Finite element simulation of blank torpedo impact on submarine hulls

• Finite element simulation of the impact of a blank torpedo against a submarine hull.
• Various FE model representations of the impact scenario are investigated.
• Numerical results validated with experimental results from drop test.

The paper presents the development, evaluation and validation of a finite element model for the simulation of the impact of a blank torpedo against a submarine pressure hull. A parametric, shell finite element model was generated and analysed using ANSYS Finite Element Package to explore the effects of different loading conditions and analysis types in the accuracy of the results. Results were compared to a series of drop tests conducted by the Australian Defence, Science and Technology Organisation (DSTO). Geometric and material non-linear models were compared against varying methods of load applications. A numerical model subjected to a concentrated load was found to provide a poor representation of the drop tests. A clear improvement in the accuracy of the results was achieved by implementing a distributed impact load case; however, a full nonlinear analysis involving large deflection, plasticity and contact was found to offer the best agreement with the experimental test results.