Goodrich 



S,000r 



7,000 - 



Fig. 3 - Sea spectra used in the analysis 



wave length are used they can be combined with a spectrum transformed from the 

 frequency base to a wave length base. The transformation is: 



[r(M] 



4 "" 2 



^■"^{^) - 



and includes the change from the energy expressed in terms of wave height, to 

 the energy in terms of wave amplitude. 



It must be appreciated that although a unique curve of significant wave height 

 versus wind speed has been used, wide variations of wave height exist in practice 

 for a given wind speed. It is assumed that using this "mean ciu-ve" and deriving 

 the resulting response spectra results in mean values of the root mean square 

 response for a given wind speed or Beaufort Number. 



600 



