Dear Jason,

I first used Aggregate Mass in ADAMS to calculate SNL 13.2MW mass moment of inertia and I used the outputs into .bmi file. The results of N.F are quite off from what I got from ADAMS (with only Twr DoFs on).

I then downloaded wind.nrel.gov/public/jjonkman/BModes/

and wind.nrel.gov/public/jjonkman/NR … Bsline5MW/

offshore part to run the Aggregate Mass in ADAMS.

I specified a rigid NRELOffshrBsline5MW_Monopile_RF with all DoFs turning off since I only want to see the mass moment of inertia.

I used FAST 2012Feb edition I believe and thus I delete the line added in the new FAST this year.

I generated ADAMS model and get the mass inertia properties as following:

The aggregate mass in the global reference frame is:

Mass : 3.500003109E+005 kg

Center of Mass :

Location : -0.4106407744, -2.3123880885E-009, 109.5667156223 (meter, meter, meter)

Orientation : 89.9989498566, 5.3861985327, 270.0010456486 (deg)

Mass Inertia Tensor :

IXX : 4.2454591844E+009 kg-meter**2
IYY : 4.2253361673E+009 kg-meter**2

IZZ : 2.5520945258E+007 kg-meter

**2**

IXY : 0.2290994561 kg-meter2

IXY : 0.2290994561 kg-meter

IZX : -1.4007405804E+007 kg-meter

**2**

IYZ : 2.8746322068 kg-meter2

IYZ : 2.8746322068 kg-meter

which I updated your .bmi, the results are quite off again.

Please help me to check I am doing the right thing.

Thanks,

Regards.

Check NREL.zip (108 KB)

BModesJJ.zip (421 KB)