Definition(s)
Dynamic Amplification Factor
Ratio of a dynamic action effect to the corresponding static action effect.
NOTE 1 For a jack-up, the dynamic action effect is best simulated by means of a concentrated or distributed inertial loadset. It is usually not appropriate to factor the static actions to simulate the effects of dynamic actions.
NOTE 2 The DAF excluding the mean values, KDAF,SDOF, can typically be obtained from a single degree-of-freedom (SDOF) calculation. In this case, it is defined as the ratio of the amplitude of a dynamic action effect to the amplitude of the corresponding static action effect for periodic excitation of a linear one degree-of-freedom model approximation of jack-up behaviour.
NOTE 3 The DAF including the mean values, KDAF,RANDOM, can typically be obtained from a random wave calculation. In this case, it is defined as the ratio of the absolute value of a dynamic action effect to the absolute value of the corresponding static action effect, each including their mean value.
NOTE 4 Adapted from ISO 19902:2007, definition 3.16.
Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global Standards