Finding Equivalent Crack Growth Rate Data for Similar Steel Alloys Paper 09 April 2015 Alex-Litvinov AFGROW Tips and Tricks, Rules of Thumb, Material data (0) A short article entitled: “Finding Equivalent Crack Growth Rate Data for Similar Steel Alloys” is now available for download. The article summarizes a method that may be useful when looking for an appropriate crack growth rate model for a material that is not directly available in AFGROW. The article includes examples for two steel alloys, but a similar approach may be used for any material. To obtain this document go to the My AFGROW section (requires log in or registration).
Predict the crack growth life of a structure containing internal through cracks in a row of fastener holes 14 March 2012 Alex-Litvinov AFGROW Tips and Tricks, Life Prediction, Rules of Thumb (0) A short paper by Mr. James Harter discussing the use of AFGROW to predict the crack growth life of a structure containing internal through cracks in a row of fastener holes is now available on the AFGROW web site. The paper provided details on the use of the Advanced Model Interface and provides a direct comparison with FEM results using StressCheck. To obtain this document (http://www.afgrow.net/userarea/) go to the My AFGROW section.
Rules of Thumb 30 September 2010 Administrator General, Rules of Thumb (0) Several Users have asked me to post some helpful "rules of thumb" that may be useful when performing life prediction tasks. While I am happy to do it, I must first state that while I have found this information to be useful, each user must take full responsibility for their own life predictions. Neither I nor LexTech take any responsibility for how this information is used. Typical Retardation Parameters Willenborg SOLR Aluminum (2.5 to 3.0) Titanium Alloys (2.2 to 2.7) Steel (1.8 to 2.2) Closure Model Aluminum (3.8 to 4.2) Crack Growth Rate Data Aluminum Alloys Threshold @R=0 (1 to 2) Note, while this is the typical range, I have seen reputable data as high as 3 in a few cases. Always look at data for a similar alloy if there are no reliable data for the alloy of interest. A typical crossing point for most aluminum alloys is approximately 1.0 E-5 in/cycle at Delta K = 10 Ksi-sqrt(in) for R=0 Also, note that a "double-knee" is typical for aluminum alloys tested in air. The first "knee" generally ocurrs at approx. 4.0E-07, and the second around 2.0E-8 in/cycle.