SPH for high velocity impact computations

SPH (Smooth Particle Hydrodynamics) techniques provide the capability to perform high distortion impact computations in a Lagrangian framework. It is also possible to link SPH nodes with standard finite elements such that solutions can be obtained for problems involving both highly distorted flow and structural response. This paper presents the basic computational algorithm which includes a recently developed Normalized Smoothing Function. It discusses issues associated with smoothing functions, smoothing distances, free boundaries, material interfaces and artificial viscosity. It also presents techniques to allow SPH nodes to interact with standard finite element grids through sliding, attachment and automatic generation of SPH nodes from distorted finite elements. Examples are provided to illustrate the capabilities, algorithms and issues.