AFGROW Version Information

The crack growth life prediction program, AFGROW, (Air Force Grow) change list.

Changes

Version 5.02.05.19, Released: November 28, 2015
  • Enhancement: Classic corner crack at a lug model tabular data improvements, please see our presentation for more information
  • Bug: Advanced model COM interface crashed when certain objects (hole or unattached crack) was deleted
  • Bug: Impossible to set beta correction for the advanced through crack at hole through COM API
  • Bug: No residual K information was available (for each output interval) in the output file when a plugin model was used
  • Bug: AFGROW crashed when a problem definition title length was greater than 80 characters
Version 5.02.04.19, Released: May 20, 2015
  • Enhancement: When advanced corner crack(s) at a hole transitions to become a through crack or a slot, the stress fraction changes to 1 for the Axial, and 0 for Bearing and Bending load cases. This is necessary because AFGROW does not currently have the Bending and Bearing solutions for he advanced through crack or slot geometries.
  • Enhancement: Added the bending load case to the advanced countersank hole with corner crack(s) model.
  • Enhancement: Added the PrePredictTest function to the AfgrowBetaPlugin Interface. The function is intended to be used to test for errors prior to the start of a prediction. If this function returns true, AFGROW will continue the prediction. If function returns false, AFGROW will abort the prediction. The function has one parameter (string). When the function returns false, AFGROW will display the string in the error description dialog.
  • Bug: In the initiation dialog, the read from file option for the Cyclic Stress-Strain data dialog crashed if the user selected the wrong file type.
  • Bug: Initiation was not converting the stress-strain data when units were changed.
  • Bug: Problem in the NASGRO material model com interface. DK0, Cth, dP, dQ were not always set correctly using the COM interface.
  • Bug: AFGROW crashed when a large residual stress table was used (>25).
  • Bug: AFGROW crashed when large tables for time dependent data were used (>25).
  • Bug: In the Advanced model interface, when a hole is located between two internal through-cracks, the right through crack jumped to the left side of the hole after transitioning to the hole.
  • Bug: Crashed when a slot was added to a countersunk hole with a corner crack on the left. Note: A slot is currently not allowed at a C/S hole, so the fix simply prevents the condition.
  • Bug: The solution for the External Circumferential Crack in a Pipe was not calculated correctly.
  • Bug: Tabular Lookup file opened incorrectly if the first character in the Material Name was a numeric value.
  • Bug: The net section area for the 2-d crack in a pipe was calculated incorrectly.
  • Bug: When a document was closed, the "New" Menu button was disabled.
  • Bug: Crack disappeared when an internal through-crack transitioned to the hole with an attached crack on the opposite side (related to bug fix #9).
  • Bug: AFGROW crashed when a through crack transitioned to the hole with a crack on the opposite side.
  • Bug: Slot with corner crack can have only axial loading, AFGROW displays all 3 types of loading.
  • Bug: AFGROW crashed when the model was switched from Plug-in to Standard solutions.
  • Modification: Disabled the K-solution filter for plug-in models (plug-in models include the K-solution inherently).
  • Bug: Status Page went blank when a large user-defined beta table was entered (>25).
  • Enhancement: Print version number of the plug-in model in the text and XML output files.
  • Bug: AFGROW crashed when the "No repair" option was selected in the repair menu.
  • Bug: For Advanced models with multiple holes, it was impossible to place a slot to the right of the last hole from the left side (right side of the specimen).
  • Bug: The “filter compression” check box in the Load tab for classic crack models with holes did not work.
  • Bug: Incorrect notifications were provided for the corner cracked hole and slot models during predictions.
  • Bug: Environment dialog crashed when an environment data file was opened.
  • Bug: A second corner crack could not be added to any hole other than the first hole from the left side of the specimen.
  • Bug: Could not set an XML output file name with the COM API.
  • Bug: It was impossible to use the beta correction capability in the Advanced Model Interface for a through crack at a hole.
  • Bug: Plug-in models did not output string parameters correctly (output was a numeric value).
  • Bug: AFGROW plug-in model crashed when more than one crack was deleted.
  • Bug: AFGROW predicted no growth for an Advanced, single corner cracked hole with an axial stress fraction of zero when a slot was placed on the other side of the hole.
  • Bug: AFGROW crashed reading an input file with tabular crack initiation data.
Version 5.02.03.18, Released: July 25, 2014
  • AFGROW crashed when the tabular lookup model was set using COM with more than 2 R-values
  • Bug fix for a crash in the advanced interface when the bearing load fraction was > 0 for a double, corner cracked hole.
  • AFGROW would send output data to the screen for advanced interface when the option "output to the screen" was turned off.
Version 5.02.02.18, Released: May 15, 2014
  • Fixed the “SHIFT+F1 Help” in AFGROW. SHIFT+F1 Help invokes a special “Help mode” in which the cursor turns into a Help cursor. The user can then select a visible object in the user interface, such as a menu item, toolbar button, or window. This action opens the appropriate help topic for the selected item.
  • Made additional updates to the AFGROW Help content.
  • Fix a bug when AFGROW would crash when the "stop crack at part through transition" propagation preference was selected for the advanced models.
  • Removed the outdated limit of 30 growth rates that was shown in the tabular lookup dialog.
  • Fixed a bug where user could not set the bending constraint for the slot case
  • Fixed an issue adding a corner crack to the hole with a slot.
  • Fixed an issue where AFGROW would crash when reading a dax file with the tabular lookup data that not include data for R=0.
  • Fixed an issue where AFGROW would randomly crash when “countersunk crack at hole” and “output to file” options were selected.
  • Added support for Office 2013
Version 5.02.01.18, Released: February 17, 2014
  • New Countersunk Hole Solution for Single/Double Symmetric Corner Cracks (Axial Load Cases only)
  • Expanding the Advanced Corner Cracked Tabular Solutions to Zero Crack Length (Interpolation)
  • Improved Offset Hole Solution for Bearing Loading
  • Updated Solution for a Single Through Crack at a Hole Under Bearing Loading
  • Expanded User-Defined Data Tables (virtually unlimited)
  • Warning Messages When K-Solution Limits are Exceeded
  • Improved COM & Plug-In Features
  • New GUI with the Ability to Move/Dock Frames
  • New Crack Closure Factor for the part throught cracks
  • New predict preference, that Pxx from affecting the transition from part-through to through crack
  • Fixed bug, when AFGROW would crash processing long spectra
Version 5.01.06.17, Released: May 1, 2011
  • Support for Office 2010
  • Ability to lock AFGROW license on the dongle
Version 5.01.05.16, Released: July 26, 2010
  • Bug fix for standard single ende through crack. The option to perform life predictions for edge crack cases where the in-plane bending is constrained was ignored.
Version 5.01.04.16, Released: July 14, 2010
  • Fix bug that would cause crash under specific conditions.
Version 5.01.03.16, Released: Jun 14, 2010
  • Bug fix for Pxx (residual strength requirement). The Pxx capability was not working correctly when a Beta Correction was applied.
  • Bug fix for the advanced models with offset crack at hole bearing offset correction calculation.

Version 5.01.02.16, Released: Jun 2, 2010
  • Bug fix for Pxx (residual strength requirement). The Pxx capability was not functioning correctly due to changes in Version 5 that allow for independent compression and tension beta values.
  • Bug fix for COM output of crack length information for advanced, offset through cracks. There was no problem with the standard output.

Version 5.01.01.16, Released: May 20, 2010
  • Spectrum filtering capability to allow users to modify spectrum tension and compression stress or load values independently
  • Stress intensity filtering capability to permit beta values for axial, bending, and bearing loading to be modified independently for tensile or compression loading.
  • A new stress intensity solution for continuing damage cracking. Corner or through cracks may be modeled at an edge notch of any depth (axial load case only).
  • Corrected the solution for cracks at offset holes growing toward the far edge of a plate.
  • Additions to the COM interface to allow beta corrections to be applied to all crack tips for advanced models.
  • Disabled the bonded repair capability. The capability is available in the U.S., but an export license is required outside of the U.S.
  • Miscellaneous bug fixes including a memory leak fix for advanced double, internal through cracks

Acknowledgement

User input was instrumental in bringing about this release. It would be next to impossible to find all bugs, major or minor, without the user base giving us their comments and suggestions. We encourage all our users to their comments and suggestions.

Previous Releases

Version 4.0012.15, Released: Aug 29, 2008
  • Addition of advanced K-solutions for non-symmetric corner cracks under bearing & bending
  • Advanced, multiple point K-solution for non-symmetric corner cracks under tension, bearing, & bending
  • Corrections to classic single, double part and through-cracked holes under bearing loading
  • Capablity to change parameters (except geometric parameters) during an analysis using COM
  • Ability to use beta correction factors for advanced cracks at a hole
  • Minor correction in the K-solution for the outside crack tips for 2 thru cracks in a plate. Only changes for (C1+C2)/d > 0.9
  • K-solution correction for a surface cracked plate in bending
  • K-Solution correction for the advanced (non-symmetric) through-crack(s) at a hole solution
  • K-Solution correction for the surface cracked pipe solution (c-direction correction)
  • Bug fix - Unable to set ultimate strength in table look-up for use w/FASTRAN
  • Included a stylesheet (.xsl) to convert xml input/output files to Word format
  • New HTML help format
  • Note: 1MB RAM is required for the advanced multiple point solutions
Version 4.0011.14, Released: Jun 29, 2006
  • Fixed a problem that was causing AFGROW to run significantly slower than earlier versions for many cases. This was a result of changes that had been made to accomodate crack IDs for the multiple crack models.
  • Bug fix for FASTRAN retardation model. The FASTRAN model was not developed to be used for multiple crack (offset cracks) cases in which it is necessary to independently calculate crack growth for multiple crack tips.
  • Expanded COM capabilities
  • Additions and improvements to the on-line help
  • Minor bug fixes and interface modifications
Version 4.0010.13, Released: Feb 03, 2006
  • Modified the K-Solutionn for the bearing load case for the Single/double corner & surface cracked classic models. The new solutions Were revised after much work had been done to compare the old through crack solutions to detailed FE analyses. The part-through cases were modified using the Newman-Raju equations along with a bearing load correction.
  • Modified the K-Solutions for the Corner and Through-the-Thickness Classic lug models. These new solutions are based entirely on detailed lug FEMs. The resulting solutions are a combination of curve fit and table look-up using these data.
  • Added a feature to the predict, preferences menu to allow users to select the pin loading boundary conditions used in the FEM for the Classic lug solutions. The default condition is to use the cosine load distribution for the corner crack until the crack reaches 70% of the thickness, then transition to the Spring boundary condition when the crack reaches 80% of the thickness. The through crack case default is the Spring boundary condition (see the help for more information.
  • Added the ability for users to develop Plug-In K-Solutions and select them from the model menu, under the "Plug-In" option. Drawing tools have also been added to AFGROW so that the user-defined plug-in models may be animated in the annimation frame.
  • Expanded COM capabilities
  • Additions and improvements to the on-line help
  • Minor bug fixes and interface modifications
Version 4.0009e.12, Released: Sep 20, 2004
  • Bug fix for the NASGRO Equation (DKthreshold variable was being calculated as Kmax(threshold) when R < 0). For all rate models (except the Forman equation), AFGROW uses Kmax in place of Delta K. As a result, we were inadvertantly using Kmax(threshold) in the NASGRO equation when we should have converted back to Delta K for use in the NASGRO equation. This bug fix was included in version 4.0008.12.11, but was re-introduced in version 4.0009.12. We apologize for our error here.
  • Bug fix for the CalculateBetas feature in the COM module.
  • Bug fix for RunFrozPredict in the COM module
  • Bug fix in the Forman equation when the Willenborg or Hsu model is used. The Willenborg and Hsu models update the effective stress ratio based on Kmax and Kmin. This happens after the Kmax and Kmin values are initially computed. The updated stress ratiois not being passed to the Forman equation.
  • Additions and improvements to the on-line help
  • Minor bug fixes and interface modifications
Version 4.0009.12, Released: Jun 7, 2004
  • Added the FASTRAN retardation model
  • Added the Hsu retardation model
  • Expanded the table-lookup database for the classic oblique crack solution
  • New Advanced Tabular Solution for double, unsymmetric corner cracks at a hole (tension, bending, and bearing loading)
  • Bug fix for the classic single and double corner cracked hole model (bending load case)
  • Changed the position and crack length definitions in the Advanced Models (Multiple Crack) Interface. The position of an object is now measured from the left edge of the plate to the center of the object. Crack lengths are now consistent with the Classic Model Interface. Interal crack lengths in the c-direction are half-lengths, a-dimensions are full lengths, cracks attached to holes are measured from the hole edge.
  • XML Input/Output
  • Ability to drag and drop input files to the AFGROW interface
  • Allow the use of a single stress ratio in the table look-up growth rate model (required for the FASTRAN retardation model)
  • Advanced (multiple crack) models now accessible through COM
  • Added the ability for users to turn off the compression adjustment in the Willenborg retardation model
  • Added the ability to enter an initial opening stress directly in the closure retardation model
  • Bug fix in the user-defined beta and residual stress table interpolation
  • Additions and improvements to the on-line help
  • Minor bug fixes and interface modifications
Version 4.0008.12.11, Released: Jun 20, 2003
  • Bug fix for the NASGRO Equation (DKthreshold variable was being calculated as Kmax(threshold) when R < 0). For all rate models (except the Forman equation), AFGROW uses Kmax in place of Delta K. As a result, we were inadvertantly using Kmax(threshold) in the NASGRO equation when we should have converted back to Delta K for use in the NASGRO equation.
  • Bug fix for time dependent spectra (time for the last cycle in each sub-spectra file was added twice)
  • Bug fix for part-through to through crack transition. AFGROW prints the part-through and through crack dimensions at transition for the same number of cycles (to show the starting point for the growth of the through crack. As a result, AFGROW was actually adding cycles twice for the stress level ocurring at the time of transition.
  • The K-Solution for two, symmetric cracks at a hole (both classic and 2-crack models) was updated to solve a problem for short crack lengths where the solution was slightly less than the single crack case. The new curve fit being used was also refined using additional FEM and published data. The difference is not large, but will be noticeable in terms of the predicted life.
  • Solved a minor bug in the 2-crack interface which caused the code to crash when the plate with was changed before any cracks or holes were added
  • Corrected a bug in the status view (bending stress ratio was incorrectly displayed as the bearing stress ratio)
Version 4.0007.12.11, Released: Feb 19, 2003
  • Fixed a bug in the double, symmetric, surface crack K-solution. A few years ago, the finite width correction for all cracked hole models was modified and the new factor was multiplied instead of divided as was previously done (since, the old correction was a secant function (1/cos())). The new factor had been inadvertently divided (copy and paste error). This was the only model affected by this error.
  • Updated the new finite width correction for all cracked hole K-solutions. This is a VERY minor change and will not be noticeable for nearly all cases. It simply reflects the latest curve fit (which had been included in the manual, but not in the code).
Version: 4.0006.12.11, Released: Feb 5, 2003
  • Added significant improvements and bug fixes to the closure model.
  • Fixed a significant bug in the implementation of the NASGRO equation. When R > 0, the equation for Kop/Kmax was incorrectly implemented.
  • Fixed an indexing bug in the interpolation routine used for beta correction as a function of crack length.
  • Modified the COM interface to allow growth rate information to be extracted as a function of Delta K (or Kmax if R < 0).
  • Minor typo/spelling fixes, updated Users Guide and Technical Manual, and updated the Dispatch Interface (COM) Manual.
Version: 4.0005.12.10, Released: Jul 24, 2002
  • Included the ability to add holes to the Two Crack Model option to allow life prediction to first failure for one or two through cracks growing from or toward holes.
  • Fixed a bug in the critical crack length routine that could cause AFGROW to hang (infinite loop) for some very limited cases.
  • Releasing a new version of the cycle counting routine to force the program to do a better job of capturing overal maximum or minimum levels when they may only be counted as a partial cycle.
  • Fixed a minor bug in the crack length vs. cycle plotting routine to allow users to change the legend.
  • Minor typo/spelling fixes and updated Users Guide and Technical Manual.
Version: 4.0004.12.10, Released: May 31, 2001
  • Added the ability to start a life analysis from any point in an input loading spectrum - only available using a COM client program. The function is: SetStartPredictFromCycle(double dCycleNumber)
  • Added a COM function to obtain spectrum information. The function is: long GetSpectrumInfo (double* dCycles, double* dLevels, double* dSubspectra, double* dMaxValue, double* dMinValue)
  • Added the ability to save an input file (*.da3) from a COM client program. The function is: SaveProblemDefFile(BSTR strFileName)
  • Fixed a bug in the output interval option which could cause AFGROW to fail to print output for several intervals immediately after transition from a part-thru to a through-the-thickness crack.
  • Minor typo/spelling fixes and updated the Dispatch Interface (COM) Manual.
Version: 4.0003.12.9, Released: Feb 09, 2001
  • Added the ability to plot crack growth curves for multiple crack dimensions.
  • Added the ability to generate a beta table for a matrix of user-defined crack lengths using the COM server.
  • Added an option to output life in hours from the COM server.
  • Corrected a minor bug in the beta solution for single and double corner cracked holes. This bug would appear in rare cases when a/c is <= 1.
  • Minor typo/spelling fixes, updated the on-line help, and changed the overlay icon in the crack growth plot view.
Version: 4.0002.12.8, Released: Sep 26, 2000
  • Added the ability to view spectrum exceedance plots.
  • Fixed a bug in the crack growth plot in cases where there are a LARGE number of cycles.
  • Fixed a bug in the animation frame when changing from English to Metric units.
  • Fixed a bug in cases where an environment file was saved inside the AFGROW input file (the full path was not being read correctly when it contained spaces).
  • Included a new version of the cycle counting tool with bug fixes and updated help infomation.
  • AFGROW will now print out large numbers of cycles (up to 9,999,999,999,999) and/or small crack lengths as required without truncation or overflow problems.
  • Corrected spelling errors in the status view.
Version: 4.0001.11.8, Released: May 19, 2000
  • Changed the default angle for the corner cracked lug to be consistant with the angles used for the corner cracked hole in a plate.
  • Corrected spelling errors in the status view, and updated the on-line help.
Version: 4.00.11.8, Released: April 24, 2000
  • Added the capability to perform life prediction for 2 independent through cracks. A drag and drop capability has been created to aid in the design of the 2-crack model. A properties dialog has also been added to support this new capability.
  • Added time dependent crack growth capability.
  • Changed the default angle for the C-direction (corner cracked hole) from 0 to 5 degrees. Included an option to change the parametric angles used to determine K in the A and C direction for part through cracks (located in the registry).
  • Added the capability to zoom in and out on the specimen view.
  • New grid control is used in all dialogs which require tabular input.
  • Updated the on-line help for the new two-crack capability.
  • This version is the first version that has been built using Microsoft Visual C++ Version 6.