In this paper, the comparison of the estimated cross-sectional stiffness matrix of a rectangular and a blade cross-section by the three semi-analytical approaches (Jung, Song and Wiedemann) and the 2D FE code BECAS (which is considered as the reference method). The paper is well written with a clear structure. Some of the minor comments are provided below for the authors to consider when preparing their revision.

• When obtaining the shear stiffness terms, a calculation model is considered with the blade tip loaded. Do you mean that a blade is assumed with the same cross-sections from the root to the tip? Moreover, is the tip load realistic to consider? In fact, a distributed line load is often used when designing the blade.
• Secondly, do you assume that the blade will experience relatively small deformations and behave as a linear beam globally? Will the geometrical nonlinearity as a blade beam influence the cross-sectional coupling stiffness terms?
• Only one blade cross-section is considered. It might be interesting to consider at least two cross-sections with different aerodynamic profiles.

In this manuscript, a number of beam cross-sectional models are compared for use in the context of early-stage wind turbine blade optimisation. This is a timely investigation into an interesting area, which is certainly worth researching. The paper is complete and generally well written. I am happy to recommend publication following minor revision for optimal clarity, but I would invite the authors to consider the points below to enhance their manuscript.

1. The paper is dotted with typos, grammatical and formatting imprecisions. I would strongly recommend another round of careful proofreading.
2. It would be good to add some comments into the manuscript on whether or not the predictions of the stiffness coefficients are mesh insensitive or, in other words, to have more details in the paper about the meshes adopted. It would also be good to have figures showing the meshes, especially around geometric details. This is because there is evidence in the literature that BECAS and VABS predictions are mesh sensitive, with fine meshes and accurate geometric representation of the cross-section being required for accurate results. See, e.g., https://wes.copernicus.org/preprints/wes-2023-85/. So, are the BECAS reference solutions converged?
3. A similar comment applies to the accuracy of the stresses. The authors do comment on the link between mesh and stress predictions, but it would be useful if that discussion could be expanded. Similarly, it would be good to see how the different models perform with the stress recovery of all stress components, not just a few. That’s particularly important for the composite models, where through-the-thickness ply-by-ply stresses are notoriously difficult to resolve.
4. I would strongly recommend considering an additional beam model that seems to have been omitted from the paper. Models from the book 'Mechanics of Composite Structures' by Kollár and Springer have proven useful in various projects, providing accuracy and efficiency.
5. I am generally diffident of code-to-code performance comparison. Computer scientists have methods to do it accurately, but, in an engineering context, so many caveats need to be added that the results very quickly lose meaning. For instance, for a fair comparison, an accurate baseline needs to be established. I’d expect the comparison to be done between models that all deliver the same accuracy, otherwise one may compare, e.g., models that are quick and inaccurate with models that are slow and accurate. Also, can the authors discern if the speed of each model is related to the mathematic formulation thereof or to the specific software implementation of that model? More basically, a computer’s OS manages the machine’s resources continuously. Comparing run time not knowing what else the computer was doing during the analysis can be very misleading.

The submitted manuscript reviews different methods to determine the cross-sectional stiffness properties of a wind turbine rotor blade on an analytical basis in comparison with BECAS. Since BECAS is a well known tool for this task it perfectly serves as a reference. The advantage of the analytical basis is adequately identified in terms of the calculation speed. This not only serves quick design space iinvestigation but as well high iteration speed in preliminary design. Therefore, the manuscript is of high relevance.

Anyhow, the results show differing deviations from BECAS for bending and torsional stiffness properties depending on complexity of the chosen cross-section. Here the deviation is reduced with increasing complexity. This seems counterintuitive. Thus, more insight into the actual calculation procedure would be helpful. Two of three chosen approaches are only mentioned and not elaborated on, which is why it will be difficult to repeat parts of the work.

All in all, the manuscript is worth of being published with minor revisions. Additional comments can be found in the pdf document attached.

Best regards.