The Research Of Slamming Load And Structural Strength Of A Semi-planning Forward Placed Outrigger High-speed Trimaran

As a new type of high performance vessel, the trimaran is a combination of outstanding abilities such as stability, high speed, sea keeping and so on. The three-body structure of the trimarans share the same main deck and superstructure, which provide the vessel broader deck space and preeminent hydrodynamic performances. Meanwhile, the trimaran structure determines the complexity of slamming load and ship structure research.In this thesis, with application of LS-DYNA simulation software, the numerical analyses of the slamming of a semi-planning forward placed outrigger trimaran are carried by the ALE method. Setting up a3-Dimentional finite element model, the numerical data stimulates the process that the trimaran is entering water, which demonstrates a pressure-time curve of the slamming load underneath each part of the vessel prow. To analyze the effects of lateral dip angle and air cushion theory on the slamming load distribution, this thesis presents a comparative study through analyzing V-shaped vessels of different lateral dip angles, trimaran models without regard to air effects, as well as models without regard to side hulls. According to the simulated results, the thesis puts forward the fitted curve of the slamming load peak value that the vessel prow bottom endured. The curve is an important reference for the design work of the trimaran bottom structure.By using ABAQUS finite element software, this thesis carried out a total strength check on this trimaran in accordance with entry-level norms of British Lloyd’s Register of Shipping on trimarans. Laboring the calculation of loads as well as specific loading methods, this thesis got the whole ship structure strength stress through direct computing, which satisfies the requirements of trimarans. The strength stress calculation on other trimarans in this thesis that complies with the entry-level norms of Lloyd’s Register Shipping regulations could be taken as constructive reference, the results and conclusions made in this thesis have reference values for the design and development of trimarans.