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Use of Timoshenko and Euler beams

Hello David,

From the documentation I understood that Timoshenko beams had already been implemented in the QBlade software. Is this however the case? I found two posts (1, 2) from last year where you mention that they will be added in the future, but has it already been implemented?

If so, I do not understand why the shear stiffness GA is put equal to zero (for example in OC4_DeepCWindSemi_Sub_LPMD.str in the SUBELEMENTS matrix) to model a Euler-Bernoulli beam when a Timoshenko beam is equivalent to a Euler beam only if . Should AG thus not be set to “infinity” or an extremely large number to model a Euler beam?

Kind regards,

Victor Rappe

Hi Victor,

the Euler-Bernoulli Beam formulation that QBlade uses at the moment simply doesnt use the shear stiffness parameter, so this value has no effect and is just used as a placeholder.

The next release (in about a months time) will include Timoshenko beams that then require the GA parameter to model blade shear deformations.

At the moment we are in the process of veryfying the Timoshenko formulation through comparisons in the IEA Wind Task 55 based on the new IEA 22MW RWT design, result will be published at this years Torque 2024 conference in Florence.

BR,

David

Hello David,

Thank you for your reply. Just to be sure: You write that the GA parameter will be required to model the blade shear deformations in the next release. However, my research considers the substructure of a FOWT. Will this release also include Timoshenko beams for the modelling of the substructure?

With kind regards,

Victor

Hi Victor,

yes, in the next release Timoshenko elements can also be used to model the substructure.

BR,

David

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