7.5 Temporal Damage Development 



In Chapter 6, the generalized Equations 6.15 and 6.16 for predicting damage 

 progression were highly correlated with damage data from Series A', B', and C. Figures 

 7. 11 through 7.14 show Equations 6.15 and 6.16 plotted against data from Series D', £", 

 F', and G'. To recap, Series D' and E' were nearly identical to Series B' except that the 

 peak wave period was changed for the three series. Series F' and G' were again similar 

 except that the uniform armor was replaced with riprap. Two different peak wave 

 periods were tested in Series F' and G'. It can be seen that the damage progression 

 equations predict the overall trend of damage progression for Series D' through G' using 

 a^ = 0.025, Up - 0.022, and h = 0.25, although there are noted discrepancies. For 

 example, it can be seen that damage initiation is underpredicted in all series. Equations 

 6.15 and 6.16 significantly underpredict damage initiation, if only 1 or 2 stones are 

 displaced at the beginning of each test series. This underprediction appears to be 

 produced by the variability in damage initiation. Figures 7.15 through 7.18 show 

 Equation 6. 15 starting from two different points: from 7V„, = and from the first 

 measured damage point past A^,^. = 1000. As can be seen, the prediction is much better 

 when the damage is predicted after initial profile adjustment. Figures 7. 1 1 through 7.18 

 indicate that the empirical coefficients in Equations 6.15 and 6.16 may vary somewhat 

 with wave period and stone gradation for the range of experimental conditions described 

 herein. The initial profile adjustment may need to be accounted for in test series with 

 relatively small cumulative damage. 



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