Dynamic amplification factor

Dynamic Amplification Factor (DAF) or Dynamic Increase Factor (DIF), is a dimensionless number which describes how many times the deflections or stresses should be multiplied to the deflections or stresses caused by the static loads when a dynamic load is applied on to a structure.^[1]

When lifting an object during a sub-sea operation, the DAF is calculated based on dynamic hydraulic forces or on snap-forces. ^[2]

${\displaystyle DAF={\frac {F_{total}}{Mg}}}$

Where:

$M$ is the mass of the object in air (kg)

$g$ is the acceleration of gravity (9.81m/s2)

${\displaystyle F_{total}}$ is the largest of ${\displaystyle {F_{static-max}+F_{hyd}}}$ or ${\displaystyle F_{static-max}+F_{snap}}$ (N)

References

1. Dynamics of structures by Anil K Chopra
2. Modelling and analysis of marine operation, DNV-RP-H103, April 2011