Integrated Design of Hull Form and Structure for Composite Double-Stepped Deep-V High-Speed Craft

Objectives To meet the integrated requirements of high speed, seakeeping performance, and slamming resistance for composite high-speed craft operating in complex nearshore swell conditions, an integrated design and experimental verification study is carried out for a double-stepped deep-V hull form and a slamming-resistant composite hull structure. Methods Based on the hydrodynamic design theory of planing craft, a large-deadrise double-stepped deep-V hull form is developed, and its drag reduction performance is evaluated through model resistance tests. A composite hull structure is constructed using carbon-fiber-reinforced marine epoxy laminates and polyvinyl chloride (PVC) foam sandwich panels. An Abaqus finite element model is established to evaluate the strength, stiffness, and stress distribution of the hull under design loads. Inclining tests, mooring tests, and full-scale navigation trials are further conducted to verify the craft’s speed performance, navigation stability, and structural integrity. Results The model test results show that, under the design maximum-speed condition, the effective power of the double-stepped deep-V hull is reduced by approximately 11.5% compared with that of the baseline deep-V hull, indicating a clear drag reduction effect. The finite element results demonstrate that the composite hull structure does not reach the failure criterion under the design load, and its overall strength and stiffness satisfy the design requirements. Full-scale trials further confirm that the craft has good high-speed navigation performance and dynamic response capability, with no obvious structural abnormalities observed during the trials. The laminate-foam sandwich structure maintains good structural integrity. Conclusions The proposed double-stepped deep-V hull can effectively improve the hydrodynamic performance in the high-speed planing stage, while the carbon-fiber laminate/PVC foam sandwich structure meets the requirements of lightweight and slamming-resistant design. The integrated “hull form-structure-test” methodology can provide a reference for the engineering design and performance verification of composite high-speed craft.