Shock Wave Impact Simulations Using Fluid/Structure/Dynamics Interactions

Ground vehicle subjecting to a blast can sustain vehicle damages and occupant injuries. Direct blast thermal and force loadings compromise vehicle structural integrity and cause damages. Computer simulations of vehicle blast wave damages can be obtained by solving the gas dynamics of the blast wave and the structural dynamics of the vehicle, through a projection of the wave's impact on the vehicle structure. There are various possible ways that the blast can cause injuries to the vehicle occupants, such as direct collision with objects instantly accelerated by the blast pressure and impact by the secondary shock waves transmitted through the platform structure. This paper describes a parallel computer simulation methodology that can potentially be applied to predict the structure damage and the associated occupant kinematics during a blast event by solving the multi-physics problem of fluid dynamics, solid dynamics, and multi-body dynamics. A generic box model was used in the demonstration of this newly-developed methodology. The generic land system structure consists of a box representing a vehicle armor structure, and a rigid body system representing a crew member in a ground vehicle. The outside generic structure is modeled as a deformable component. The shock wave generated by a blast impacts the outside structure and the gas dynamics of the shock wave propagation is solved by an Eulerian finite volume method with a block structured, adaptive mesh refinement and immerse boundary method in the Cartesian coordinate. The thin-shell structure solver computes the large deformation of thin surface-like solids. To discretize the thin shell, subdivison finite elements based on Loop's schemes are used. A numerical solver for the six-degree of freedom equations of motion has been developed using Newton's second law and solved numerically by using a Runge-Kutta method, providing time-accurate simulations of body motion. Simulations, using multiple computer processors, of the outer box deformation and the motion of the inner box due to the shock wave transmitted through the deformed wall will be presented in this paper. Simulation results for cases ranging from free air blast to blast over a hemispherical dome are also reported.