ANTIPASTO: An interactive mesh generator and preprocessor for two-dimensional analysis programs

ANTIPASTO is an interactive two-dimensional preprocessor based on innovative user interface concepts, newly-developed geometric modeling and mesh generation algorithms, and device-independent graphics. It allows the analyst to generate, with greatly reduced effort, a complete input file for many finite-element programs including the DOE programs PASTA2D, TACO2D, GNATSII, NIKE2D, and DYNA2D. ANTIPASTO uses composite parametric cubics to store all lines and curves necessary to construct a mesh. Closed curves are supported because they allow more natural problem descriptions. The HPM algorithm developed at the University of California at Davis allows element meshes to be generated within arbitrarily complex regions with curved sides. ANTIPASTO currently supports the meshing of regions with one, two, three, four, five and six sides. Through the use of powerful grouping commands, elements, nodes, and boundary nodes can be identified and combined into named groups. The group names are available for use in specifying material properties, initial conditions, and boundary conditions such as constraints, loads, and slidelines. Groups can be specified in geometric terms. For example, all the elements within an arbitrary closed curve can be added to a group. This concept of geometric problem specification has several important implications. First, the analyst need not ever be concernedmore » with node or element numbers. The model is completely described in terms of its geometry. Second, the mesh can be modified without the need to modify any other part of the model description. Finally, global mesh modification commands (such as a command to refine the entire mesh) can also be used without affecting any other part of the model description. ANTIPASTO presently runs on VAX computers under VMS and on CRAY computers under UNICOS. Versions for SUN and Macintosh workstations are being developed.« less