Section 220.127.116.11. Spectra Descriptions
The stress history uniquely defines the sequence and magnitude
of the individual stress events applied at a specific location. While this information is essential for
conducting a cycle-by-cycle crack growth analysis that accounts for load
interaction, it is both difficult to use and interpret without computer
programs that perform such analyses.
One of the side benefits associated with describing flight-by-flight
crack growth rates as a function of a characteristic stress-intensity factor is
that one is forced into presenting stress history information simply. This subsection addresses two such schemes –
the exceedance curve and an RMS characterization.