LIGGGHTS 2.3.1: (released 28 March 2013)
+ Released a new fix couple/cfd/force/implicit for use with CFDEMcoupling that uses a dragforce that varies with particle velocity rather than a constant one on the DEM side.
A couple of small updates for fix insert/*:
+ Added output of fix-ID to insertion info, which can be helpful in case multiple insertions are used.
+ Fixed an issue where in some cases no particles were inserted for cases with large # of procs (e.g. 128). Thanks to Sam Bateman (USNRL) for bringing this up.
A couple updates for wall handling:
+ Added a fix_modify option to fix mesh/surface/stress/servo which enables the user to change the target value during the simulation. Thanks to Andreas Aigner (JKU) for adding this functionality
+ Fixed an issue with the new fix mesh/surface/stress/servo where an unfix operation led to a misleading error message. Thanks to Xuetao Wang (Züblin Stuttgart) for flagging this.
+ Fixed an issue with consistency of the wiggle and riggle styles of fix move/mesh across simulation restart and multiple runs. Thanks again to Sam Bateman (USNRL) for posting this issue.
+ Fixed a bug where the conveyor feature did not set the surface velocity correctly for all ghost elements in parallel. Thanks to Christian Richter (OVGU Magdeburg) for flagging this issue.
+ Fixed 2 issues with store_force yes for fix wall/gran/* where values where not correctly computed/initialized in some cases. Thanks to François Guillard (Universités à Aix en Provence) for sending a patch.
+ Fixed an issue with shear history in relationship to primitive walls where the particle-contact releationship could get messed up for some particles upon leaving the domain. Thanks again to François Guillard (Universités à Aix en Provence) for noting this.
Further updates:
+ Included a patch from Andreas Aigner (JKU) that resolves an arg parsing issue with pair/gran/hooke/history/hysteresis.
+ Fixed a small communication issue with fix ave/euler and a dump problem in parallel with dump euler/vtk.
+ Added another patch for the CMake build system. Thanks to Anton Gladky (TU Freiberg) for the hint.
+ Fixed a couple minor typos in the doc and added a doc file for fix wall/region/sph.
However, there are some restrictions in 2.3.1 (see below) which will be relaxed over time:
+ fix breakparticle/force is not yet available