What's New in Zencrack?

Zencrack 7.4a

Zencrack version 7.4a was finalised on 28 July 2006

Version 7.4a is an interim release extending the capabilities of the original version 7.4 release. A number of bugs have been fixed in this release. In addition some enhancements are available.


  • The PC Windows version of Zencrack 7.4a is available for the Compaq Visual Fortran compiler and the Intel Fortran compiler. This is the first release available using the Intel compiler. The setup program which should be run after installation allows selection of the Fortran environment and Zencrack binaries. This gives users the opportunity to maximise compatibility with the requirements of their finite element code when using user subroutines. Compiler versions used for this release are Compaq Fortran 6.1a and Intel Fortran 9.0.
  • A new command line option "-o" has been added. This is an extension of the existing OVERWRITE option which is set to either YES or NO in the runzcr74 script file to define whether or not a job should overwrite existing output from a previous run. The command line option "-o yes" or "-o no" can be used to override the setting in the script file.
  • Routines that calculate the position of out-of-plane crack face nodes have been made more reliable for cases where the out-of-plane growth is significant.
  • The element sets ZCRSPLITsss created for the split pairs have been separated into two sets - one for each side of the crack front. This is relevant in the Abaqus and Marc interfaces where the new split set names are ZCRSPLITxxxSIDEn and ZCRSPxxxSn respectively. The separation of the element set into two sets helps during post-processing.
  • A warning is issued when the license file is close to expiry.
  • A new crack-block, st12x1, is available.
Crack-block st12x1
Crack-block st12x1
Shaft under tension-torsion loading using the new crack-block st12x1
Shaft under tension-torsion loading using the new crack-block st12x1

Abaqus interface

  • In Abaqus 6.5-4 there were changes to the ordering of the output in the .dat file. This meant that Zencrack 7.4 (and earlier versions) could not extract data from the .dat file for Abaqus 6.5-4 or later. This is now addressed with Zencrack 7.4a. At the time of release Zencrack 7.4a was tested with Abaqus versions up to and including 6.6-1.
  • Stress intensity factors are now calculated from displacements taking into account large displacements in an analysis with NLGEOM=YES. This is intended for use in large displacement - small strain analysis.
  • K factor and T-stress output can be requested for all VCE sets rather than just for the "straight ahead" VCE set.
  • A restart option is added to allow re-run and continuation of analyses. The option removes the requirement to re-run any previously completed Abaqus analyses in the event, for example, of a power failure during a crack growth analysis.
  • The Abaqus keyword file keyabq.dat is updated for versions up to Abaqus 6.6-1.

Ansys interface

  • The Ansys keyword file keyans.dat is updated for versions up to Ansys 10.0 SP1.

Marc interface

  • The supplied IMPD user subroutine is modified to improve compatibility as new Marc versions are released.
  • The Marc keyword file keymar.dat is updated for versions up to Marc 2005r3.

Utility program PROCESS

  • The columns for raw contour integral values are extended to allow all values to be reported for the largest crack-blocks. Previously there was a limit of seven contours even though some crack-blocks could calculate more that seven contours.
  • Multiple raw contour integral values can now be processed for analyses run with the Finas interface. Previously only contour 1 was reported.