Thank you for the opportunity to review the Manuscript wes-2025-180 entitled "Geometric Nonlinear Analysis of Timoshenko Beams with Variable Cross-Section Using Co-rotational Formulation" for the Journal of Wind Energy Science.

To the best of my knowledge, I have thoroughly reviewed the manuscript, and I would recommend in accept the manuscript based on my review.

Thanks again for providing the opportunity to contribute the review support to maintain the quality standard of Wind Energy Science Journal.

I look forward to contributing more review support, so please share any additional manuscripts within my area of expertise. Thank you!

Thank you for the opportunity to review the manuscript wes-2025-180 entitled "Geometric Nonlinear Analysis of Timoshenko Beams with Variable Cross-Section Using Co-rotational Formulation" for the Journal of Wind Energy Science.

Having thoroughly reviewed the manuscript, I find that the study is well-conducted and presents valuable insights in its field. Overall, the research is of good quality; however, there are certain points and details in the analysis and presentation that would benefit from further clarification and revisions to enhance the clarity and impact of the work.

I appreciate the opportunity to contribute to the review process and support the maintenance of high-quality standards in the Journal of Wind Energy Science.

The authors formulate a co-rotational Timoshenko beam element for large displacement analysis of 3D frames, considering the influence of variable cross-section. The solution of the equilibrium equations is used to interpolate the lateral displacements and rotations for improving the element efficiency. Numerical examples and experiments are carried out to confirm the accuracy of the element. The topic is of interest, but many issues should be clarified for further evaluation of the paper.

• Primarily, the solution of the equilibrium equations of a Timoshenko beam with variable cross-section is difficult to derive. The author should provide more details on the derivation of the solution and the considered section profile. I believe that a solution for a general section cannot be derived. Additionally, the number of Gauss points used to evaluate the element tangent stiffness and mass matrices depends on the profile of the beam section. It is difficult to evaluate the element without knowing this information.
• The authors claim that “the proposed method achieves both high computational efficiency and accuracy in handling large deformations and nonlinear behavior”, but the efficiency is not demonstrated in the paper.
• The presentation should be improved. Section 3 presents the co-rotational framework, which is well-known in the literature, but no references are cited. A 3D beam is considered, but the equilibrium equation (1) is written for a 2D beam. An explanation for Eqs. (1)-(3) should be given.
• More information on the large deformation behavior of the structure, such as snap-through and snap-back, is required to show the efficiency of the element and numerical algorithm.