Simulating IEC DLC 1.6

Wind & Water General
1

Dear all,

I’m running extreme load analysis with FAST for jacket substructures. While looking further into the selection of simulation parameters I came across this clause in IEC 61400-3: “Calculation of DLC 1.6b may be omitted if in the treatment of DLC 1.6a, the non-linear wave kinematics are properly represented in the dynamic simulations of the severe stochastic sea state”

Are the here mentioned non-linear wave kinematics sufficiently covered by enabling the second-order waves?
How do you deal with load case 1.6a and 1.6b?

Many thanks in advance and kind regards,
Manuela

2

Dear Manuela,

The answer probably depends on the water depth, wave length, and wave height (wave steepness). Often wave kinematics are simulated in load case 1.6a with a constrained wave simulation (which is not functionality available in the current version of FAST/HydroDyn). See Appendices C and D for more information.

Best regards,