Frequency analysis of floating structure

Wind & Water Structural Analysis
1

Hi everybody,

I am working with the concept of a rotatable tower on a floating support structure for my Master’s thesis.

I want to be able to estimate the first natural frequency of the tower using a simplified model with a lumped mass at the tower top and a rotational spring and damper to model the influence of the mooring system and the hydrodynamic loads acting on the floating support structure. The reason for this simplified approach is that I am doing a preliminary design and therefore need to have a very general way of estimating the influence of changing i. e. the dimensions of for example the draft and the diameter of the support structure on the natural frequencies.

Have anybody knowledge of how this can be performed or know of some relevant literature.

Best regards

Jacob Pedersen

2

Dear Jacob,

If you can write the linearized equations of motion, you should be able to derive the system eigenfrequencies.

Best regards,

3

Dear Jason,

Thanks for your reply.

I will look into that.