ON THE FEASIBILITY OF USING SMOOTHED PARTICLE HYDRODYNAMICS FOR UNDERWATER EXPLOSION CALCULATIONS

SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian techniq ue which is appealing as a possible alternative to numerical technique s currently used to analyze high deformation impulsive loading events. In the present study, the SPH algorithm has been subjected to detaile d testing and analysis to determine the feasibility of using PRONTO/SP H for the analysis of various types of underwater explosion problems i nvolving fluid-structure and shock-structure interactions. Of particul ar interest are effects of bubble formation and collapse and the perma nent deformation of thin walled structures due to these loadings. Thes e are exceptionally difficult problems to model. Past attempts with va rious types of codes have not been satisfactory. Coupling SPH into the finite element code PRONTO represents a new approach to the problem. Results show that the method is well-suited for transmission of loads from underwater explosions to nearby structures, but the calculation o f late time effects due to acceleration of gravity and bubble buoyancy will require additional development, and possibly coupling with impli cit or incompressible methods.