A problem about the effect of centrifugal force in ElastoDyn

Dear Jason.Jonkman

I am tring to get the generalized stiffness of blade with ElastoDyn model. I find that the stiffness including the effect of centrifugal force (KBECent and KBFCent) is calculated in subroutine Coeff. But it seems that the KBECent and KBFCent are not merged into KBE and KBF. I find that the KBECent and KBFCent are local variable in the subrotine Coeff while the KBECent and KBFCent are only influenc the damp of balde (CBE and CBF). So how the centrifugal force effects the blade stiffness in Elatodyn.

Thank you

JiYuan.Men

Dear JiYuan,

Correct, the centrifugal stiffness calculated within SUBROUTINE Coeff() of ElastoDyn is computed locally, only for the purposes of estimate natural frequencies and damping. The actual centrifugal stiffness calculated by ElastoDyn as part of the time-domain solution is implemented through the kinetic quantities within the equations of motion.

Best regards,

Dear Jason.Jonkman

Thank you for your help! As your answer, does it meas that the blade velocity includes rotor speed accroding to kane equations and the centrifugal effect need not be calculated separately anymore?

Thank you

JiYuan.Men

Dear JiYuan,

Yes, that is correct. The blade kinematics include the rotor speed and many other terms.

Best regards,