In this paper we apply semi-geodesic trajectories to the creation of isotensoid domes for filament wound pressure vessels. The governing equations for the determination of the meridian shapes and related winding angle distributions of domes are derived using the netting analysis and the semi-geodesic winding law. The effects of the slippage coefficient on the geometry and fiber trajectories of the domes are respectively evaluated in terms of the resulting meridional curves and fiber angles. It is revealed that the semi-geodesic angles and the dome depth have an overall decrease with increasing the slippage coefficient. The results also demonstrate that the use of semi-geodesics significantly enlarge the design space for the geometry and adapted fiber trajectories of the domes. The present method can provide a significant reference for the design and production of the domes for semi-geodesically overwound pressure vessels.

The goal of this paper is to present non-geodesic trajectories for filament wound truncated conical domes for pressure vessels. The fiber trajectories for non-geodesically overwound truncated conical shells are obtained based on differential geometry and the non-geodesic winding law. The influence of the slippage coefficient on non-geodesic trajectories is evaluated in terms of the winding angle distributions. The non-geodesic trajectories corresponding to various initial winding angles are also illustrated for the given slippage coefficient. The results show that the winding angle distribution of non-geodesics on a truncated conical dome has an overall increase with the increase of the slippage coefficient or the initial winding angle. The present method can provide a significant reference for developing non-geodesically overwound conical structures.

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The inherent complexity of large ships makes it challenging to evaluate ship designs systematically and scientifically. Knowledge-based expert systems can be reasonable solutions. However, this problem needs more rationality and better operability, especially in complicated ship-equipment suitability evaluation problems with numerous indicators and complex structures. This paper presents a hybrid multi-criteria decision-making (MCDM) framework to extend the ship-equipment suitability evaluation to group decision-making settings, where individual consistency and group consensus are thoroughly investigated to improve rationality and operability. As a result, an improved Interpretive Structural Modeling (ISM) method is developed to construct the evaluation index systems. Furthermore, based on an applicability analysis of the selected MCDM methods, an improved Analytical Hierarchy Process (AHP) method is proposed to distribute the index weights, and an applicable Fuzzy Technique for Order Preference by Similarity to Ideal Solution (Fuzzy TOPSIS) method is utilized to evaluate and select appropriate ship designs. Finally, a ship-equipment environmental suitability evaluation case is examined. The results indicate that the proposed framework improves the rationality and operability of the decision-making process and provides practical support to decision-makers for the systematic and scientific evaluation of ship designs. Therefore, it can also be applied to other ship design evaluation and selection problems.

In view that present traditional composites forming technologies are difficult to guarantee the processing quality of complex components such as components with small curvature radius or with concave-convex surface. this paper used the fiber placement technology, and in order to achieve the single independent and overall joint movement control of each fiber tows ,it adopted the mainstream open control mode of a PC machine combined with a programmable multi-axis motion controller . At the same time, it introduced a feedback system to realize the accurate pressure control of multiple fiber tows, so as to ensure the quality of fiber placement.