Effect of the Torsion Box Dimensions on Local Stress Distribution and Fatigue Strength Assessment of a Container Ship

Round 1

Reviewer 1 Report

This paper focuses on the estimation of the influence of the dimensions of the torsion box on local stress distribution and local fatigue strength. Although the overall parts are carefully prepared, some clarifications are still needed before it can be accepted for publication.

1. The basic assumption for mathematical equations in the Section 2 should be described in details. 

2. How to obtain gamma function in Eq. 17?

3. How to define the material properties, such as stress-strain relation, Poisson's ratio, etc, for modelling? Independent tests for such properties should be added as a supplement for clarification. 

4. The mesh sensitivity analysis should be performed for the meshing pattern in Fig. 4.

5. What is the failure criteria used in the modelling? This should be added together with the experimental failure modes.

6. The thick curves in Fig. 9~Fig. 12 are not clear while the plotted results should be clarified as mises of principal stresses from modelling.

7. In conclusion, some more explanation should be given for the "high cost".

Author Response

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Reviewer 2 Report

The purpose of the manuscript is to investigate the influence of the dimensions of the torsion box of a 2400TEU feeder-class container ship, on local stress distribution and assessment of local fatigue strength by using a numerical approach.  The work is well driven and interesting.

Minor revision

1. The relationships need the bibliographic source. There are known relations for the calculation of structures subjected to torsion.

2. Details are missing regarding: discretization element size, discretization method.

3. A quantitative approach to life cycle would have been very useful.

4. Deformation forms of structures subjected to buckling would be useful. Of course, here I would also add values of the total deformations.

Author Response

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Reviewer 3 Report

In reviewer's opinion, the paper can be recommended for publication in Journal of Marine science and Engineering with addressing the reviewer's comments listed below:

- The novelty of this research should be highlighted in the abstract and conclusion.

- Recent references (2021-2022) should be added and discussed in the introductory section.

- Section 2.1. Please add a reference to Fricke et al. (2002).

- Please Scheck the character used for the equations, as there is a difference between the character used in equations 1-7 and the others.

- Section 3. a table of the description of the material characteristics should be added.

- Section 4. A sensitivity test of the mesh elements used in this simulation should be performed along with a description of the elements.

- a validation with real tests from other references, if the experiment is not possible, is necessary to verify the efficiency of the numerical model used.

- The quality of the curves plotted in Figures 7-12 should be improved; the size of the markers should be reduced...

Author Response

Please, find attached the answers in the .doc file

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