HELP, A Multi-Material Eulerian Program for Compressible Fluid and Elastic-Plastic Flows in Two Space Dimensions and Time. Volume 1

Volume I details a new numerical model for solving multi-material flows which are functions of two space dimensions and time. The program, called HELP, is basically Eulerian but also contains Lagrangian features for the explicit definition of interface positions. The program is general in the sense that any number of materials can be present in a given Eulerian cell and no special difficulties arise for flows involving extreme material distortions. The program is suitable for compressible media with strength dependence. Compressibility is included by an equation of state giving pressure as a function of density and specific internal energy. Strength is included by means of a constitutive equation giving the deviatoric stresses as functions of the elastic and plastic strains. In this Volume I report, the basic equations are developed, the computer program is documented and sample results are given from six applications.