Strip Theory 



1.4 Formula for Determining the Wave Bending Moment 



From the analysis of the total set of results, a formula was produced which 

 seems to cover all possible cases: 



c = 10-3 [(3.38 ^ 11 20 X) C + (1.94- 71.63 \- 21.38 Fr) p - (1.91- 12.45^ 



where ^ = i/l . 



Hence, the wave bending moment can be immediately deduced as " 



' '■ ■ M = c X ^ g BL^ ■ '■'• '■■'■ 



By a comparison between the values given by the above formula and those 

 calculated, it can be noted that the differences distribution follows with sufficient 

 accuracy the Gauss law, with a mean value equal to zero and variance o-'^ ~ 1.5. 

 The error probability is given by Table 3. 



Table 3 

 Error Probability 



Consequently, it would seem entirely justified to use, in any actual case of 

 maximum wave bending moment calculations, the values provided by the above 

 formula in lieu of those obtained according to the KK method; it is not, in fact, 

 expected that the difference between the values obtained according to the KK 

 method and the real values on the actual ship may be restricted within limits 

 more narrow than those above. It is however, to be well kept in mind that the 

 validity limits of the formula lie within the field of the values selected for the 

 systematic calculation, particularly as far as Froude number and sea state are 

 concerned. 



The preceding formula can be written in the form: 



c = K, K, X 10"-^ , 



m 1 2 



where 



K^ = f (\, C^, Fr. p) 



829 



