Rayleigh |
 
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Rayleigh |
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The standard case is a timetrace in which all of its points follow a Gaussian (normal) distribution. The individual maxima in the timetrace are Rayleigh distributed. The Rayleigh cumulative distribution is defined by:
(1)
where m0 denotes the variance (zeroth spectral moment) of the timetrace and the maxima are measured as amplitudes above the mean. The estimate of the extreme maximum and minimum values is determined from Extreme Value Principles (Eq.1) and (Eq.2) and Equation (1) above:
(2)
where σ denotes the standard deviation of the timetrace (s = m00.5 ). In the case that the structural response has a non-zero mean μ, the extreme value becomes:
The number of maxima N is computed from:
where ncount denotes the number of maxima counted in the timetrace. The storm duration and the duration of the timetrace are for example 3 and 0.5 hours, respectively.
•*STATISTICS is used to request the creation of statistics plots.
•*EXTREMA is used to specify the procedure and input parameters to be used in the computation of extreme values.
