Creating a Failure Analysis Diagram (FAD) from Tensile Test Data

F.A. Conle
Updates: Oct10 2013
Copyright (C) 2013 F.A. Conle
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is available here:
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The purpose of a FAD Failure Analysis Diagram is to check if the progress of
a propagating crack will endanger the component for plastic collapse/fracture.
Details of the process can be found in British Standard BS7910 : 2005 Section 7 pg.23.
A brief statement of the Failure Analysis Diagram found there is:

       "The vertical axis of the FAD is a ratio of the applied conditions, in
        fracture mechanics terms, to the conditions required to cause fracture,
        measured in the same terms.  The horizontal axis is the ratio of the 
        applied load to that required to cause plastic collapse."

Example Diagram:

Example Tensile test input file:

Program to compute points in FAD table:
getFADs.f (click on RAW button to download)

         Program usage:   ./getFADs   fadsTableFile

Resulting FAD table:

Script to plot FAD table:
plotFADs (Linux bash script for gnuplot)

        Script usage:  ./plotFADs  fadsTableFile

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