Air Gap Response of Floating Structures: Statistical Predictions Versus Observed Behavior

Summary and Conclusions • A new, fractile-based approach has been proposed to definean amplification factor,b p , on extreme wave crest levels due todiffraction. This is calculated as the rms-ratio between input andoutput peaks in all wave cycles ~Eq. ~8!!. The scaling factor re-sulting from this new approach is found to describe the outputfractile results quite well, even at extreme levels within the 18 hof seastate test results, e.g. Figs. 5–7.• Figure 8 shows that the largest observed amplification,roughly 1.4, is found at location 1 ~in front of the up-wave col-umn; see Fig. 1!. Other near-column locations ~4, 5, 6, and 9!show amplification factors of roughly 1.2. As might be expected,somewhat greater amplifications generally occur for the smallerT P case ~with shorter wavelengths, hence larger relative effect ofthe structure!. The largest amplifications, however, at the near-column locations are relatively constant for the two T P cases con-sidered.• An analogous amplification factor, b