Dear Daniel,
Regarding K_ShrFlp and K_ShrEdg, I’m not sure. The flapwise and edgewise shear stiffness were never defined for the NREL 5-MW baseline blade. Qi Wang (the lead developer of BeamDyn who has now departed NREL) assembled this BeamDyn model and set those values. I would expect the shear stiffness to have a negligible response for this blade (due to the high aspect ratio and lack of bend-twist coupling), so my guess is, Qi set values that had a negligible effect on the response and did not cause numerical problems (being too high or low).
Regarding mX_cm, mY_cm, and i_cp, “yes.” But actually, m*Y_cm is zero in the BeamDyn input file of the NREL 5-MW baseline turbine in Test #26 of the FAST CertTest, but is nonzero in the BeamDyn input file of the NREL 5-MW baseline blade in the BeamDyn CertTest. The former was set so as to better compare the results of Test #26 (with BeamDyn) with Test #18 (without BeamDyn) in an “apples-to-apples” fashion. The latter better matches the data defined in the NREL 5-MW specifications report. i_cp is zero in the NREL 5-MW specifications report because the orientation of the principle axes of inertia are not defined separately from the orientation of the principle axes of bending (and so, are assumed to be coincident).
I hope that helps.
Best regards,