A truss-floating aquaculture vessel is an innovative addition to the aquaculture industry, characterized by its large, porous, ship-shaped structure. It differs from traditional ships, offshore structures, and individual net cages. Due to its distinctive features, a large-scale truss-floating aquaculture vessel requires dedicated hydrodynamic and structural analysis, which is the primary focus of this paper. Our study starts with the calculation of wave loads acting on the vessel using the equivalent design wave method. Subsequently, it delves into the analysis of structural characteristics and stress distribution of the truss-floating aquaculture vessel, upon which structural optimization is performed. To determine the optimal design variables, a sensitivity analysis of the truss members is carried out using a parametric research method. Finally, the structure with multiple objectives is optimized using two distinct approaches: the adaptive simulated annealing algorithm (ASA) and the multi-island genetic algorithm (MIGA). The results reveal that prior to optimization, there is a risk of buckling and yielding damage occurring at various connections within the vessel structure. After optimization, the structural strength is significantly improved, accompanied by a reduction in the total weight of the vessel. This study offers a valuable reference for the design and structural safety assessment of this innovative truss-floating tank-type aquaculture vessel.

The moving particle semi-implicit (MPS) method is employed to investigate the dynamic response of a wave energy converter (WEC) buoy subjected to dam-break flows. The buoy is connected to a hydraulic power take-off (PTO) system equipped with an accumulator, enabling it to capture wave energy. First, the MPS method is validated by comparison with experimental results, demonstrating its accuracy in simulating violent interactions between dam-break flows and the buoy. Subsequently, numerical simulations are conducted to analyze the influence of different PTO forces and buoy positions on the heave motion, fluid forces and captured power of the buoy. The results indicate that PTO force exerts a significant influence on heave motion, captured power and vertical fluid force while having a relatively minor effect on the horizontal fluid force. In addition, the maximum power that the buoy can capture increases as its distance from the wall decreases. Notably, the maximum average captured power of the buoy located near a wall can be five times higher than that of a buoy far away from the wall, indicating that a vertical wall can significantly increase the efficiency of nearshore WEC devices. These findings could provide valuable insights for the design, optimization and operation of nearshore WEC devices.

Offshore floating photovoltaic (FPV) platforms have attracted attention as a promising approach for expanding solar energy utilization in marine environments. However, the hydrodynamic behavior of connected FPV arrays and the associated mooring response under realistic offshore conditions remain insufficiently understood. In this study, a numerical model of a connected offshore FPV platform array designed for the East China Sea is established using frequency-domain hydrodynamic analysis and time-domain simulations. The effects of module spacing and connector configuration are first examined for a twin-float system, and the optimized connection scheme is then applied to a 4 × 4 array. The motion responses, air-gap variation, and mooring performance of the array are evaluated under operational and extreme sea states. The results show that the surge response of the array is governed by an edge amplification effect under operational conditions, whereas the array tends to exhibit a more coordinated, quasi-rigid-body response as environmental loading increases. The heave response is influenced by wave shielding among adjacent units, while the pitch motion is strongly synchronized by the spring–damper connection system. The air-gap and mooring analyses indicate that the platform maintains sufficient freeboard and mooring safety margins under the considered sea states. These findings provide useful guidance for the preliminary design and safety assessment of connected offshore FPV arrays.