Utility software

Two utility programs are provided to further post-process the Zencrack results:

• "process" - generation of data for plotting results at crack front nodes
• "3dmesh" - generation of crack growth profile plots.

Process

The "process" utility program allows generation of a csv (comma separated variable) file containing detailed information for one or more nodes on a crack front. This allows easy importing of data into a spreadsheet where the results can be plotted and analysed. This type of processing is essential in order to understand the large amount of data that can be generated in an analysis.

A Microsoft Excel template is supplied to allow plots to be quickly generated from the csv file. The template is intended for use with a crack growth analysis but can readily be modified for other applications (e.g. single f.e. steps with multiple sets of results through a time history).

When using the template with results from a crack growth analysis, graphs are automatically available for:

• Sum of da vs Cycles (for fatigue and combined fatigue/time dependent growth analysis)
• Sum of da vs Time (for time dependent and combined fatigue/time dependent growth analysis)
• Stress intensity factors vs Sum of da
• Energy release rate vs Sum of da
• %Error in sqrt(G) terms vs Sum of da (this graph indicates solution accuracy).

3dmesh

The "3dmesh" utility program allows the crack growth history to be represented by a f.e. mesh that can then be viewed in a pre-processor. For example:

Profiles for a model with 3 crack fronts viewed in Abaqus/Viewer (growth remains below threshold at several points)	Profiles for a symmetry model of a semi-elliptic surface crack viewed in Ansys	Profiles for an inclined crack in a plate viewed in MSC.Mentat

The output from 3dmesh may also be superimposed on the uncracked mesh to allow visualisation of the profiles against the specimen geometry. For example:

Crack growth profiles from utility program "3dmesh" superimposed on the uncracked mesh