LIGGGHTS 2.3.3: (released 16 May 2013)
+ Added an initial version of the EPSD (elastic-plastic spring-dashpot) rolling friction model, implemented by Andreas Aigner (JKU). See Ai et al, Powder Technology, 206 (3), 269–282 for details on the model.
+ Andreas Aigner (JKU) also made multiple improvements to the servo walls (fix mesh/surface/stress/servo) - thanks for this.
+ Implemented wall contact tracking for non-history wall styles (e.g. wall/gran/hooke, wall/gran/hooke/stiffness). This will result in better edge/corner contact detection and handling for non-history wall styles.
+ Added documentation for fix ave/euler and dump euler/vtk. Also fixed a small bug in fix ave/euler where a group ID other than "all" was not processed correctly.
+ Fixed an unwanted behavior in fix mesh/surface where non-normalized axis lead to extra scaling/rotation. Thanks to Pete Falkingham for the note and a testcase.
+ Fixed an issue which could arise when an insertion region for fix insert/pack is highly divided across many processors.
+ Fixed a rare memory issue with dump mesh/VTK for dumping certain parameters.
+ Also a small bugfix in dump mesh/stl where files had missed out the footer line in some cases. Thanks to the guys from Overland Conveyor for the note.
+ Improved the primitive wall neighlists that were actually too large in some cases. Thanks to Sam Bateman (USNRL) for the note.
+ Fixed a small issue in compute pair/gran/local when heat transfer properties were dumped and the group used was not "all".
However, there are some restrictions in 2.3.3 (see below) which will be relaxed over time:
+ fix breakparticle/force is not yet available