HEMP, 2-D Elastic Plastic Flow in 2-D X-Y or Cylindrical Geometry by Lagrangian Method

1 - Description of problem or function: The HEMP code solves the conservation equations of two-dimensional elastic-plastic flow, in plane x-y coordinates or in cylindrical symmetry around the x- axis. Provisions for calculation of fixed boundaries, free surfaces, pistons, and boundary slide planes have been included, along with other special conditions. 2 - Method of solution: The solution is by the method of finite differences and uses the Lagrangian formulation. The materials within a physical system are divided into quadrilaterals bounded by J and K grid lines. A decoupling of grid lines is allowed along K-lines, and voids may open and close between K-lines. 3 - Restrictions on the complexity of the problem: The maximum number of J's in any K-line is 101. A problem of up to about 10,000 zones may be run