
Institut für
Leichtbau und StrukturBiomechanik
INTRANET 

ARIGEN INPUT FILES: VOLUME FRACTION RECORD
This documentation pertains to ARIGEN Rev. A2LI/012.
An ARIGEN volume fraction record contains two or more lines, the first of which
consists of the keyword
*VOLUME FRACTIONS
In the second and following lines different algorithms can be called up,
each of which increases the inhomogeneity volume fraction of the volume
element.
At present the following options may be used
 RSI, target_VF, max_attempts:
random sequential insertion to target volume fraction
target_VF with a maximum of
max_attempts insertion attempts;
if no maximum number of attempts is given a default of 24999999 is used.
 SEG1, target_VF, max_steps or
CMS1, target_VF, max_steps:
type 1 (original) Segurado MonteCarlo compression to volume fraction
target_VF with a maximum of
max_steps compression steps;
if no maximum number of steps is given a default of 50 is used.
 SEG2, target_VF, max_steps, num_incs
or
CMS2, target_VF, max_steps, num_incs:
type 2 (modified) Segurado MonteCarlo compression to volume fraction
target_VF with a maximum of
max_steps compression steps;
if no maximum number of steps is given a default of 50 is used.
The parameter num_incs is optional;
it describes the number of increments to be used to go from the RSI
volume fraction to the SEG2 target volume fraction; if no number of
increments is specified ARIGEN tries to choose a suitable value.
 CSHF,target_VF, num_incs, shift_factor,
shift_cutoff, compression_mode, random_contribution:
pseudorepulsiveforce based vectorial shifting compression to volume
fraction target_VF in
num_incs increments (from the RSI
volume fraction to the CSHF target volume fraction);
if no number of increments is given a default of 10 is used.
The other 4 parameters are optional and are defined as follows:
 shift_factor: a multiplier for
the shifts of the inhomogeneities, which has a default value of 0.3
 shift_cutoff: a corrector added
to the minimum distances having a default value of 1.0E06
 compression_mode: can take values
of 0 for a deterministic algorithm, 1 for an "axial Monte Carlo" algorithm
and 2 for a full Monte Carlo algorithm, the default being 0
 random_contribution: random
contribution in Monte Carlo modes with a default value of 0.
The first generation step must be of type RSI and later generation steps cannot
be of type RSI.
ARIGEN Rev.A2L/011 is limited to sequences of two algorithms, i.e., an RSI
step followed by a compaction step.