Numerical and experimental analysis of response of a floating platform to underwater explosion

All new war ships or any new submarine design, or any undersea weapon such as torpedoes, should be designed to survive extreme loading conditions, such as underwater explosions (UNDEX). One can carry underwater explosion shock trials to validate design. However, these shock trials require years of planning and preparation and are extremely expensive. The cost involved and the environmental effects require exploration of numerical solution techniques that can analyze the response of any new design subject to various explosions. Computational modeling and response, if perfected, can effectively and accurately replace the experimental procedures used to obtain the UNDEX response on real structure design. The computational modeling also provides a valuable tool for design validation during early design phase. In this study, underwater explosion simulations which have been defined by related international military standards, on a floating shock platform were carried using the finite element package ABAQUS. The effect of fluid mesh size, cavitations and damping on the response of the structure was investigated. As a second step, same shock conditions have been applied on the structure which has been manufactured according to the same international standard for experimental analysis. Experiments have been carried out on black sea coast near to Istanbul with the control of military personnel. The signals from strain gauges and 3-axial shock accelerometers have recorded with very high sampling frequency for different explosion conditions. Results of numerical analysis and experiments have been compared to validate the numerical model. Once the method has been validated by experimental results, the same procedure can be reliably used to evaluate the response of any warship or shipboard equipment to underwater explosions.