Design And Research On Light Structure Of High-speed Trimaran Ship

The high speed trimaran is a new kind of high performance ship developed during the recent years. In contrast with a monohull ship, it has the advantages including minimized drag, good rapidity and excellent seakeeping characteristics and enlarged deck areas. If served as military vessel, the trimaran even has the advantages of good protection capability, good breakage stability, convenient for the dispersing arrangement of armament systems and the operating of helicopters, as well as the good confidentiality. As a result of these superiorities, the high speed trimaran has very bright developing prospects both on warship and civil ships. Many researches have been done on the high speed trimaran domestic and foreign, which the content mainly focused on the aspects so as hydrodynamic force theory, model experiment and conceptual design and so on, quite few are about the trimara structure' design and research.As a result of its special complex hull structural style of high speed trimaran, it will certainly to withstand very large crosswise wave bending moment and torque, so the component size must be enlarged to ensure the structure strength during the structural design, but at the same time, the overall structural weight would be greatly increased. However, no matter which kind of high speed ship, is extremely sensitive to its own weight. How to solve the contradiction between reducing the hull weight and ensuring the structural strength has become one of the most important questions need urgently solving in the high speed trimaran' structural design.The most important structure in the trimaran is the cross connecting structure. This paper conducted the research of light structure design of the cross connecting structure mainly by two ways which are namely the light construction material design and the light structural style design. At the beginning of this paper, three kinds of light construction materials were introduced. Then, the loading cases which the cross connecting structure withstanding were demonstrated, and three kinds of main loadings were chosen for the later research. While optimizing the structural style of the cross structure, three plate girder structural models were designed according to the rules, which are transverse frame system, the longitudinal frame system and densely reinforced structure system. The stress and response characteristic of the three models were analyzed under each of the three loading cases. The structure style which suits the connect structure better was determined through the contrast analysis.Three-dimensional section structural model at the region of trimaran's cross structure was designed in this paper. In which connection bridge structure has respectively designed as model constructed by aluminum alloy and the high-tensile steel. The weights of these two models were contrasted. Finite element analysis has carried out on the two models under the three loading cases, and the stress characteristic of alloy aluminum nature cross connection structure was analyzed and summarized.At last, the connecting structures of the main hull and the cross structure as well as the side hull and the cross structure were locally optimized according to the stress distribution characteristic of the cross structure, and three models were designed. Then, computation and the contrast analysis research had been carried out on the three models under the three loading cases, and conclusions were made which would provide the references for the later structure design of trimaran.