Sandia Engineering Analysis Code Access System (SEACAS)
Also known as ACCESS
Privacy and Security Notice| Code | Description | |
|---|---|---|
| General Information | ||
| Overview | The Sandia National Laboratories (SNL) Engineering Analysis Code Access System (SEACAS) is a collection of structural and thermal codes and utilities used by analysts at SNL. The system includes pre- and post-processing codes, analysis codes, database translation codes, support libraries, UNIX shell scripts, and an installation system. | |
| Using SEACAS on Parallel Computers |
DRAFT. Instructions to run the SEACAS/ACCESS system on Parallel computers. Currently specific to Sandia National Laboratories systems. | |
| Analysis Codes | ||
| JAS3D | JAS3D is a three-dimensional finite element program
designed to solve large quasi-static nonlinear mechanics
problems. The continuum equations describe nonlinear
mechanics involving large rotation and strain, which are
iteratively solved using either nonlinear conjugate gradient
or dynamic relaxation algorithms. At present, several
constitutive material models are incorporated into the
program. They include models which account for elasticity,
viscoelasticity, several types of hardening plasticity,
strain rate dependent behavior, damage, internal state
variables, deviatoric and volumetric creep, and
incompressibility. The code also has the capability to apply
a variety of mechanical time-dependent loads to a
model. JAS3D has mechanisms to calculate coupled response in
conjunction with other-physics codes, such as thermal,
electrical, or chemical-kinetics. Arbitrary contacting
surfaces between bodies are accounted for, which allows many
physical processes to be modeled realistically. The contacts
can be tied together, slide without friction, or slide with
friction, and can be allowed to open and close as the
solution dictates. (This document is still in review. Contact Mark Blanford (mlblanf@sandia.gov) for more information.) |
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| Pronto3D | PRONTO 3D is a three- dimensional transient solid
dynamics code for analyzing large deformations of highly
nonlinear materials subjected to extremely high strain
rates. This Lagrangian finite element program uses an
explicit time integration operator to integrate the
equations of motion. Eight- node uniform strain hexahedral
elements and four- node quadrilateral uniform strain shells
are used in the finite element formulation. An adaptive time
step control algorithm is used to improve stability as well
as performance in plasticity problems. Hourglass distortions
can be eliminated without disturbing the finite element
solution using either the Flanagan- Belytschko hourglass
control scheme or an assumed strain hourglass control
scheme. All constitutive models in PRONTO are cast in an
unrotated configuration defined using the rotation
determined from the polar decomposition of the deformation
gradient. A robust contact algorithm allows for the impact
and interaction of deforming contact surfaces of quite
general geometry. The Smooth Particle Hydrodynamics method
has been embedded into PRONTO using the contact algorithm to
couple it with the finite element method. The following reports are available:
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Coyote (Theory) Coyote (Users) |
The COYOTE computer code is a general purpose program package designed for the solution of heat conduction problems and other types of diffusion problems. The code is based on the Galerkin form of the finite element method (FEM). The class of problems treated by COYOTE are basically those described by the standard heat conduction equation. The capability to simulate surface-to-surface radiation in conjunction with the thermal conduction problem is also available in COYOTE; capabilities for treating chemically reacting materials are supported in the software package. Though specifically intended for the solution of heat conduction problems, the code can be used for a wide variety of boundary and initial value problems. This generality stems from the analogy between the heat conduction equation and other diffusion equations encountered in engineering and physics. A partial list of application areas that are analogous to the heat conduction problem are: Saturated or partially saturated flow in porous media, Potential fluid flow, Electrostatic fields, Electric conduction, Mass diffusion, and Lubrication flows. Many of these types of problems may be solved with COYOTE in either the steady-state or transient form. | |
| Support (Preprocessing, Postprocessing, Manipulation) Codes | ||
| Algebra | The ALGEBRA program allows the user to manipulate data from a finite element analysis before it is plotted. The finite element output data is in the form of variable values (e.g., stress, strain, and velocity components) in an EXODUS database. The ALGEBRA program evaluates user-supplied functions of the data and writes the results to an output EXODUS database which can be read by plot programs. | |
| Aprepro | Aprepro is an algebraic preprocessor that reads a file containing both general text and algebraic, string, or conditional expressions. It interprets the expressions and outputs them to the output file along with the general text. Aprepro contains several mathematical functions, string functions, and flow control constructs. In addition, functions are included that, with some additional files, implement a units conversion system and a material database lookup system. | |
| Blot | BLOT is a graphics program for post-processing of finite element analyses output in the EXODUS database format. BLOT produces mesh plots with various representations of the analysis output variables. The major mesh plot capabilities are deformed mesh plots, line contours, filled (painted) contours, vector plots of two/three variables (e.g., velocity vectors), and symbol plots of scalar variables (e.g., discrete cracks). Pathlines of analysis variables can also be drawn on the mesh. BLOT's features include element selection by material, element birth and death, multiple views for combining several displays on each plot, symmetry mirroring, and node and element numbering. BLOT can also produce X-Y curve plots of the analysis variables. BLOT generates time-versus-variable plots or variable-versus-variable plots. It also generates distance-versus-variable plots at selected time steps where the distance is the accumulated distance between pairs of nodes or element centers. | |
| MUSTAFA | MUSTAFA is a Motif GUI driven, full-featured data
visualizer for unstructured grid data in the EXO-DUS II
database format. MUSTAFA is built with the Express
application development environment (AVS Inc.) which makes it
fairly easy to modify and extend to support other data
formats, special vi-sualization methods, etc. MUSTAFA
supports both nodal and element based data.
MUSTAFA has four main components: (1) data readers, which actually read the data from disk and set up data structures; (2) data filters, which only manipulate the data or mesh; (3) visualization methods, which actually produces a viewable object; and (3) viewers, which display the results of the visualization methods onto the computer screen and provide for user specified geometric transforma-tions. Multiple simultaneous data readers and viewers are supported. MUSTAFA's visualization tools are divided into four primary groups depending upon what kind of data they work on:
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| Cubit | [See the Cubit web page for more information.] The CUBIT mesh generation environment is a two- and three-dimensional finite element mesh generation tool which is being developed to pursue the goal of robust and unattended mesh generation-effectively automating the generation of quadrilateral and hexahedral elements. It is a solid-modeler based preprocessor that meshes volume and surface solid models for finite element analysis. A combination of techniques including paving, mapping, sweeping, and various other algorithms being developed are available for discretizing the geometry into a finite element mesh. CUBIT also features boundary layer meshing specifically designed for fluid flow problems. Boundary conditions can be applied to the mesh through the geometry and appropriate files for analysis generated. CUBIT is specifically designed to reduce the time required to create all-quadrilateral and all-hexahedral meshes. Contact: CUBIT Mailing List (cubit-dev@sandia.gov). | |
| ExoSym | EXOSYM helps analysts produce more realistic looking visualizations of analysis results and models. EXOSYM reads as input a three-dimensional finite element mesh or results file in EXODUS [1] format and will mirror the geometry and results about the specified coordinate planes. | |
| GenShell | GENSHELLis a three-dimensional shell mesh generation program. The three-dimensional shell mesh is generated by mapping a two-dimensional quadrilateral mesh into three dimensions according to one of several types of transformations: translation, mapping onto a spherical, ellipsoidal, or cylindrical surface, and mapping onto a user-defined spline surface. The generated three-dimensional mesh can then be reoriented by offsetting, reflecting about an axis, revolving about an axis, and scaling the coordinates. GENSHELL can be used to mesh complex three-dimensional geometries composed of several sections when the sections can be defined in terms of transformations of two-dimensional geometries. | |
| Gen3D | GEN3D is a three-dimensional mesh generation program. The three-dimensional mesh is generated by mapping a two-dimensional mesh into three-dimensions according to one of four types of transformations: translating, rotating, mapping onto a spherical surface, and mapping onto a cylindrical surface. The generated three-dimensional mesh can then be reoriented by offsetting, reflecting about an axis, and revolving about an axis. GEN3D can be used to mesh geometries that are axisymmetric or planar, but, due to three-dimensional loading or boundary conditions, require a three-dimensional finite element mesh and analysis. More importantly, it can be used to mesh complex three-dimensional geometries composed of several sections when the sections can be defined in terms of transformations of two-dimensional geometries. | |
| GJoin | GJOIN is a two- or three-dimensional mesh combination program. GJOIN combines two or more meshes written in the GENESIS mesh database format into a single GENESIS mesh. Selected nodes in the two meshes that are closer than a specified distance can be combined The geometry of the mesh databases can be modified by scaling, offsetting, revolving, and mirroring. The combined meshes can be further modified by deleting, renaming, or combining material blocks, sideset identifications, or nodeset identifications. | |
| Grepos | GREPOS is a mesh utility program that repositions or modifies the configuration of a two-dimensional or three-dimensional mesh. GREPOS can be used to change the orientation and size of a two-dimensional or three-dimensional mesh; change the material block, nodeset, and sideset IDs; or "explode" the mesh to facilitate viewing of the various parts of the model. | |
| Grope | GROPE is a program that examines the input to a finite element analysis (which is in the GENESIS database format) or the output from an analysis (in the EXODUS database format). GROPE allows the user to examine any value in the database. The display can be directed to the user's terminal or to a print file. | |
| Mapvar | MAPVAR is designed to transfer solution results from one finite element mesh to another. MAPVAR draws heavily from the structure and coding of MERLIN II, but it employs a new finite element data base, EXODUS II [3], and offers enhanced speed and new capabilities not available in MERLIN II. In keeping with the MERLIN II documentation, the computational algorithms used in MAPVAR are described. User instructions are presented. Example problems are included to demonstrate the operation of the code and the effects of various input options. | |
| Numbers | NUMBERS is a program which reads and stores data from a finite element model described in the EXODUS database format. Within this program are several utility routines which calculate information about the finite element model. | |
| nem_slice | nem_slice reads in a FEM description of the geometry of a problem from an ExodusII file, exoIIfile , generates either a nodal or elemental graph of the problem, calls Chaco to load balance the graph, and outputs a NemesisI load-balance file. | |
| nem_spread | nem_spread reads it's input command file (default name nem_spread.inp), takes the named ExodusII and spreads out the geometry (and optionally results) contained in that file out to a parallel disk system. The decomposition is taken from a scalar Nemesis load balance file generated by the companion utility nem_slice. Here is an example nem_spread input file. | |
| nem_join | nem_join reads it's input command file (default name nem_join.inp), takes the parallel file description and the named ExodusII, combines the results (located in the paral- lel files) and writes them to the ExodusII file. Here is an example nem_join input file. | |
| Libraries | ||
| ExodusII | EXODUS II is a model developed to store and retrieve data for finite element analyses. It is used for preprocessing (problem definition), postprocessing (results visualization), as well as code to code data transfer. An EXODUS II data file is a random access, machine independent, binary file that is written and read via C, C++, or Fortran library routines which comprise the Application Programming Interface. (exodusII is based on netcdf) | |
| Netcdf | The netCDF software functions as an I/O library,
callable from C or FORTRAN, which stores and retrieves data
in self-describing, machine-independent files. Each netCDF
file can contain an unlimited number of multi-dimensional,
named variables (with differing types that include integers,
reals, characters, bytes, etc.), and each variable may be
accompanied by ancillary data, such as units of measure or
descriptive text. The interface includes a method for
appending data to existing netCDF files in prescribed ways,
functionality that is not unlike a (fixed length) record
structure. However, the netCDF library also allows
direct-access storage and retrieval of data by variable name
and index and therefore is useful only for disk-resident (or
memory-resident) files. An HTML version of the documentation is available for the C Interface and the Fortran Interface Additional netcdf information is available from Unidata (http://www.unidata.ucar.edu/packages/netcdf/index.html). Man pages for the ncgen and ncdump utilities are also available. (These can be used to convert an exodusII file from/to a text representation.) |
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| Nemesis | NEMESIS I is an enhancement to the EXODUS II nite element database model used to store and retrieve data for unstructured parallel nite element analyses. NEMESIS I adds data structures which facilitate the partitioning of a scalar (standard serial) EXODUS II le onto parallel disk systems found on many parallel computers. Since the NEMESIS I application programming interface (API) can be used to append information to an existing EXODUS II database, any existing software that reads EXODUS II les can be used on les which contain NEMESIS I information. The NEMESIS I information is written and read via C or C++ callable functions which compromise the NEMESIS I API. | |
| SUPES | SUPES is a col lection of subprograms which perform frequently used non-numerical services for the engineering applications programmer. The three functional categories of SUPES are: (1) input command parsing, (2) dynamic memory management, and (3) system dependent utilities. The subprograms in categories one and two are written in standard FORTRAN-77, while the subprograms in category three are written to provide a standardized FORTRAN interface to several system dependent features. | |
Last modified: Tue Feb 10 11:33:07 MST 1998