A structural optimization method for floating dock gates based on an improved particle swarm–simulated annealing algorithm

Floating dock gates are large-scale marine structures whose performance and stability are closely related to structural weight and stability. This study addresses the multi-objective optimization of floating dock gates. First, a marine component library is established to discretize optimization variables. An improved particle swarm optimization–simulated annealing (IPSO-SA) algorithm is proposed to resolve issues in the existing particle swarm optimization–simulated annealing algorithm. For multi-objective optimization, a multi-objective particle swarm optimization–simulated annealing (MOPSO-SA) algorithm is introduced, and its performance is validated through numerical simulations and comparisons with existing methods. Finally, the proposed methods are applied to a typical floating dock gate structure optimization. Using the developed component library, a parametric model is created and optimized. The multi-objective optimization reduces the weight by 11.303% and lowers the centre of gravity height by 2.5%. These improvements enhance both the economic performance and structural reliability of the original design.