The submitted draft of the diploma thesis represents a well-prepared theoretical foundation for the intended research topic focused on the fatigue behaviour of welded thin-walled structures. The student demonstrates a good understanding of the basic mechanisms of fatigue failure, fatigue crack initiation and propagation, as well as the specific issues associated with welded joints.

The introductory theoretical chapters are logically structured and written in appropriate technical English. The author successfully summarizes the fundamental fatigue concepts and introduces the main approaches used in fatigue assessment of welded joints according to relevant international standards, particularly EN 1993-1-9, IIW Recommendations, and ISO standards. The explanation of stress evaluation methods, including nominal stress, hot-spot stress, and notch stress approaches, is generally clear and technically correct.

A positive aspect of the work is the ability to connect material fatigue theory with practical engineering applications. The discussion of residual stresses, weld geometry, and fatigue categories demonstrates a solid orientation in the topic and an understanding of the practical importance of fatigue assessment in welded structures.

At the current stage, however, the thesis remains focused primarily on the literature review and theoretical background. Several key objectives of the assignment are still missing or only outlined in chapter structure form. In particular, the following parts require substantial further development:

analysis of thin-walled welded structures and the influence of wall thickness, surface quality, and welding imperfections, comparison and critical evaluation of experimental results from the literature, design of the tensile fatigue test specimen, proposal of the experimental testing methodology, methodology for evaluation of S–N curves and fatigue life, final discussion and synthesis of the obtained knowledge.

The current text is therefore not yet sufficiently balanced between theoretical and applied aspects of the topic. The practical and original contribution of the thesis will depend mainly on the quality of the forthcoming analytical and experimental chapters.

From the formal point of view, the thesis is generally written at a good academic level, although several sections still contain placeholders or incomplete passages that must be finalized. Some figures and references should also be more thoroughly discussed and properly linked to the text.

Overall, the work completed so far can be evaluated positively. The student has created a good theoretical basis for the remaining parts of the thesis and demonstrates appropriate technical knowledge of the topic. Nevertheless, significant work is still required, especially in the practical and analytical sections, which will be essential for the final quality and completeness of the diploma thesis.

The thesis deals with the issue of fatigue in thin-walled welded joints. The introductory literature review focuses on basic concepts in the field of metal fatigue as well as specific approaches used in the area of welded joints – it provides an overview of applicable standards and describes the main analytical approaches based on nominal stress, hot-spot stress, effective notch stress and fracture mechanics. The main part of the thesis specifically addresses thin-walled welded structures, discussing among other things the effects of weld geometry, residual stresses and especially wall thickness and the type of loading (bending versus tension, or a combination) on fatigue life, supported by experimental data and empirical relationships taken from the literature. It is stated that fatigue properties from tensile and bending tests are generally not equivalent and using characteristics determined under bending loading for fatigue analyses of parts predominantly loaded in tension can be dangerous. In accordance with the assignment, a test specimen of the welded joint for tensile loading is proposed, along with a test program and methodology enabling the determination of the corresponding S-N curve. 

The content of the thesis corresponds to the assignment and the approaches used as well as the technical terminology are correct. However, the thesis is written rather briefly, with some formulations and even equations excessively repeated. Given the literature-review nature of the work, more adopted experimental data could have been included, which would have better supported the formulated conclusions.