DATS.fatigue provides a comprehensive set of programs for the fatigue & durability test engineer. The DATS software allows all of the fatigue analyses to be easily automated for efficient data classification.

Fatigue analysis may be broadly categorized under the following headings:

• Cycle Counting
• Component Data (Material Selection)
• Life Prediction

The first and one of the most important stages is to collect a sufficiently long representative signal of the strain imposed on the structure. Typically signals are recorded from strain gauges sited near to a critical part of the component. After the signal is captured, typically using a Prosig P8000 system, then the data manipulation stage begins by finding the peaks and troughs (turning points). This data can then be analyzed with one of the many life prediction functions. However, before using a life prediction procedure it is necessary to select the material from the database. The combination of the turning points and the material data means the components life prediction can now be made.

Fatigue life estimation is divided into two classes all of which are based upon an increment of fatigue occurring for every stress-strain cycle.

The two basic analysis categories are...

• measured stress range versus number of cycles to failure curves, (S-N curves)
• strain life and critical location methods based upon cyclic strain history

These two approaches effectively consider that the material has fatigued when a crack is initiated. This type of analysis is most appropriate for use with highly stressed parts such as a car axle where the time between crack initiation and final failure is short.

DATS.fatigue contains all of the functions and tools available in DATS.toolbox and adds all of the features described above.