Over the years the introduction of new Computer Aided Engineering (CAE) software into the design process allowed engineers to significantly shorten the time necessary to produce finished designs. There seems to be an agreement that using CAE tools shortens the time of the design process and improves the quality of finished products. Although, oftentimes in research it is the improvement in quality, which is focused on when presenting new tools. However, in an industrial setting, what also matters and is frequently the main concern are the improvements in time efficiency. It would be undesirable for the newly incorporated software to elongate the process. In this study, the effects of incorporation of a new CAE tool on the design process is researched in an industrial setting. The opportunity, which allowed for this research is the incorporation of a new post-processing software for the finite element analysis Jan De Nul Marine Engineering and Design Department. In order for the new tool to be implemented, its effects on the design process should be tested. In order to do that, the methods of design were researched in order to find what is the current design methodology and its structure. This is done based on a case study, a draghead gantry for a trailing suction hopper dredger vessel. In this case study the equipment is designed according to the methodology used in the department. Based on the first design, the methodology of design used in the department was codified. Then, problems which were found in that process are addressed and a new design methodology is proposed based on the solutions, literature and adaptation to the new software. Next, the new design process is presented. Lastly, the results of both approaches are shown and compared.

Offshore installation vessels are growing in size in order that they are capable of handling the next-generation 15 and 20MW wind turbines. At the same time, it is important to gain a better understanding of their structural behaviour using the finite element (FE) method. One approach that is often used is the full vessel FE analysis, which studies the vessel in its entirety. However, the drawbacks are that a coarse mesh must be adopted to have an acceptable simulation time and it takes months to create a 3D model of a vessel. Another approach is the partial vessel FE analysis, which considers only a section of the vessel. This research aims to develop a methodology for the partial vessel FE analysis of an offshore jack-up installation vessel. The studied section of the vessel is between the four legs, which is where the highest bending moment is expected and the wind turbine towers are located on deck. The methodology was developed to analyse the vessel in still water and waves separately. The boundary conditions and hull girder load adjustments of the partial vessel model were described, which cause the vessel section to reflect the behaviour of the full vessel. The procedure to apply the loads on the model was also given. The finite element analyses were performed and the stress results compared to a simple analytical solution of the vessel based on Euler-Bernoulli beam theory. The methodology of the partial vessel FE analysis was successfully applied to the offshore jack-up installation vessel. For the vessel in still water, the stress results were in agreement with the analytical solution. The results were accurate in the middle region for approximately 50% of the partial vessel model and thus it is advised to have a larger model for future use. The effect of torsion could not be fully justified as it is not captured in the analytical solution, but resulted in a significant improvement. For the vessel in waves, the stress results also showed a good agreement with the analytical solution. The accuracy depended on the equivalent design wave approach, which assumed a regular travelling wave. Lastly, it was proven that the presence of payload only leads to local changes in the stress field, but not in the global behaviour of the vessel.