Research On Efficient Design Method Of Main Hull Arrangement

Ship design is a complex engineering system which relates to a lot of discipline domains. On the basis of satisfying the norm and criterion requirements, the designers complete the design tasks one by one according to Evans' Design Spiral Theory, hoping to get a ship design which meets all the task requirements at last. Due to the limit of traditional design conditions and design tools, the ship design can only be a one-direction procedure. This process can't take the link of each step into account which will get itself involved in two problems. One is that any local modification to the scheme will cause the redesign of the subsequent processes. The other is that all the finished parts should be redesigned if the design plan is not feasible. Those problems lead to lots of design resource and time wastes, which also reduce the efficiency of ship design. Therefore, based on the theory of design spiral, an innovative design method is presented in this dissertation, which is bidirectionally reversible along the design spiral. The design references and design constraints needed by following design processes are prefabricated in current design task, by which characteristic attributes of different design tasks are associated. For the application of bidirectional design theory, a series of research work are conducted. Specific studies are the following:Based on the expression methods of ship form, lines plan and offset sheets, the hierarchical relationship and logical structure among the design elements in ship form design are analyzed. At the same time, the data structure of ship form is determined on account of the relevance of characteristic attributes. Based on the geometric features, the information about ship form can be obtained through the parametric design method, which is more comprehensive and accurate. The design relationship is studied in order to add the design references and design constraints in the data structure. According to the data structure of ship form, the attributed formula and 3-D modeling method are developed to implement the rapid design and revise of ship form. The goal which is to achieve the reversal feedback of ship form design is realized.Based on the inner hull structures of cargo in different types of ships, the parametric expression method of the inner hull structure is presented to aid ship subdivision. Based on the parameters of inner hull structure, the computing system of cargo capacity is developed to calculate the flotation and stability automatically. With the maximized cargo capacity and minimized ballast capacity as the optimization objective, the improved particle swarm optimization algorithm is presented to optimize the ship subdivision under the constraints of principles and norms. The proposed algorithm is used in the engineering examples of 50000 DWT oil tanker and 174000 DWT bulk carrier, which achieves better results.The characteristics and constraint conditions of ship pipe routing are studied. From the economic perspective, the mathematical model of ship pipeline optimization is built. Based on the ant colony optimization algorithm and genetic algorithm, an improved ant colony optimization-genetic algorithm is presented to solve single pipe routing problem. Some calculative strategies are proposed according to the arrangement method and process of pipe routing to enhance the computational performance. After the arrangement methods of multiple and branchy pipe routing are analyzed, a co—evolutionary algorithm, based on the mutualism of the same populations, is proposed to solve multiple-pipe routing problem. The feasibility and advancement of the proposed algorithm are proved throght the examples.Based on the procedure and criterion of arrangements in ship engine room, the relationship between the facility layout and pipe routing is studied. Based on the relationship between the locations of equipment and pipelines, the mathematical model of engine room arrangement is presented. Based on the mutualism of the different populations, a co-evolutionary algorithm is proposed to optimize the engine room arrangement. The particle swarm optimization and the improved ant colony optimization—genetic algorithm are applied as the evolutionary processes of facility layout and pipe routing, respectively. Finally, an optimal arrangement scheme of engineer room can be obtained, in which the facility layout and pipe routing both are in the best effect. The simulation results of numerical example and engineering example demonstrate the feasibility and advancement of the proposed algorithm.For the problem of redesign in ship designing process, the bidirectionally reversible design method is presented in this dissertation. Based on the attributed data structure of ship form, the researches on ship subdivision, pipe routing and engine room arrangement are carried out. Meanwhile, the design method and optimization method are presented. Therefore, the innovative design method in this dissertation is proved to have an important influence not only on avoiding repeating the design aimlessly, but also on improving the design efficiency and design quality.