Documentation

1. DOWNLOAD

Download the zipped tar archive "pandemo.tgz" from the website http://www.get-pandas.com and extract the tar archive with the unix command "tar -xvzf pandemo.tgz". Now you should have a directory "pandas" with the following structure:

  pandas  
  |-- 1d : 1-d example problem
  |-- 2d : 2-d example problem
  |-- compile : compilation shell script
  |-- netlibs  
  |   |-- include : 3rd party header files
  |   `-- lib : 3rd party libraries
  |-- manual.pdf : PANDAS manual
  `-- src : PANDAS source files

 

2. COMPILATION

For the compilation of PANDAS make sure that all necessary libraries are installed on your system (in doubt ask your system administrator). Note that default Linux installations, e.g. of SuSE Linux 8.2, usually do not include the following required packages:

  -- gcc : GNU C compiler
  -- gfortran : GNU Fortran compiler
  -- make : GNU make command
  -- libncurses and libncurses-dev : curses libraries and development utilities
  -- libX11-6 and libX11-dev : development utilities for X11


Now change into the pandas directory to compile PANDAS. This free demo version includes two example boundary-value problems (BVP), namely a 1- and a 2-d consolidation problem (see item (4)). To compute these BVP's, PANDAS has to be compiled with the command "compile ", e.g. "compile 1d". If no error occurs, you should see something like "... was successful: 1d/pandas.". The PANDAS executable was then automatically copied into the respective problem directory. Note that the problem specific compilation of PANDAS allows the free programming of arbitrary boundary conditions.

3. RUNNING PANDAS

After the compilation change into the respective problem directory and start the created executable of PANDAS by typing "pandas" on the shell command line. The PANDAS main window is built up in the terminal window in which the executable was started. For a proper display make sure that your terminal window has at least a size of 80x24 characters (standard VT100). Note that the graphical user interface (GUI) is not available in this free demo version. Now run the prepared command file by typing "run cmd" on the PANDAS command line and follow the calculation in the visualization window. For more details on the BVP's see item (4). A short overview on some commands of PANDAS can be found in the PANDAS reference card given in the file "refcard.pdf".

If PANDAS does not run properly, please check your default language setting with the command "echo $LANG". The environment variable should be set to "C" (e.g. in a bash type "export LANG=C" or in a tcsh "setenv LANG C"). In the case that you run a newer SuSE Linux distribution with German as the default language, LANG is set by default to "de_DE@eu" and PANDAS will produce a core dump since it expects commas instead of points in floating point numbers. For further help on specific problems, please feel free to contact the PANDAS support via email (support'AT'get-pandas.com).

4. EXAMPLE PROBLEMS

Brief introduction to the 2 BVP's: *)

  -- 1d : A fluid-saturated elastic column in an impermeable rigid tub
  (uniaxial deformation and fluid flow)


The simplest benchmark to show the consolidation behavior is given by a linear elastic porous medium saturated by a viscous and materially incompressible pore-fluid that is embedded in a rigid and undrained (impermeable) tub (ger. "Wanne"). Applying a constant force on the drained (permeable) top side of the tub, a pore-fluid pressure is developed inside the porous medium forcing the fluid to stream out of the drained surface. In general, this behavior is known as the consolidation process. For further details, see the PANDAS manual (manual.pdf).

  1d  
  |-- 1d.bc : free programmable boundary condition file
  |-- 1d.geom : geometry definition file
  |-- cmd : command file
  |-- out : output file (after computation)
  |-- out.log : logging file (after computation)
  |-- pandas : pandas executable (after compilation)
  |-- posihook.ivars : definition of internal variables to store
  |-- posihook.param : material parameter file
  `-- quad.shape : definition of finite element type

 

  -- 2d : A rigid slab on a fluid-saturated elastic half space
  (plain strain condition)


The deformation behavior of e.g. soil under a foundation can be described by a displacement driven simulation. Here, a rectangular domain of a fluid-saturated linear elastic material is subjected to a time-dependent displacement on half of its top side, while the incompressible pore-fluid can only stream out through the drained (permeable) unloaded part on the top. During the simulation the deformation behavior, the pore-fluid pressure distribution, and the pore-fluid flow (seepage velocity vectors) are shown in the visualization window. Extending the physical model by elastoplastic skeleton properties (not part of the free demo version), the so-called base failure problem can be described by simulation of the shear band development.

  2d  
  |-- 2d.bc : free programmable boundary condition file
  |-- 2d.elems : element definition file (preprocessed)
  |-- 2d.geom : geometry definition file
  |-- 2d.nodes : node definition file (preprocessed)
  |-- cmd : command file
  |-- out : output file (after computation)
  |-- out.log : logging file (after computation)
  |-- pandas : pandas executable (after compilation)
  |-- posihook.ivars : definition of internal variables to store
  |-- posihook.param : material parameter file
  `-- quad.shape : definition of finite element type


Note that the demo version of PANDAS is restricted to the quasi-static, 2-d (plain strain) geometrically linear theory only including linear elastic skeleton properties (material modul posihook). Moreover, only quadrilateral TAYLOR-HOOD mixed finite elements and a direct profile solver are provided. Time and space adaptive strategies are also not part of the free demo version.

*) A more detailed documentation of the example problems is given in the PANDAS manual (manual.pdf).

5. SYSTEM REQUIREMENTS

In general, PANDAS is running on any platform with a Unix or Linux operating system. Focussing on PC's and workstations running under Linux, a standard installation including the X graphics package and some additional developer tools is required. Note that the required developer packages

  -- gcc : GNU C compiler
  -- gfortran : GNU Fortran compiler
  -- make : GNU make command
  -- libncurses and libncurses-dev : curses libraries and development utilities
  -- libX11-6 and libX11-dev : development utilities for X11


are usually not part of a default installation.

For a convenient computation of the BVP's included in this free demo version, the following minimum hardware requirements are suggested:

  -- CPU PII 200 MHz
  -- RAM 64 MB
  -- free disc space 20 MB
  -- standard color graphics board

 

6. SUPPORT

For the free demo version of PANDAS an email support is provided via support'AT'get-pandas.com
More informations on the software package PANDAS can be obtained from info'AT'get-pandas.com