An intelligent semi-active bridge pier protection system with MR-STF damping and TSO–DBO optimized fuzzy control

To address the limitations of traditional ship–pier anti-collision systems, which often fail to simultaneously protect both structures and vessels and lack adaptive control, this study proposes a novel semi-active intelligent anti-collision system. The system integrates a progressive magnetorheological shear-thickening fluid damper into a conventional fender structure, enabling adaptive response to varying impact conditions. A variable-universe fuzzy proportional–integral–derivative control scheme, enhanced by an inverse hyperbolic sine scaling mechanism, is developed to govern the damper's response. To further optimize control parameters and membership functions, a hybrid metaheuristic algorithm combining Tuna Swarm Optimization (TSO) and Dung Beetle Optimization (DBO) is proposed. Numerical simulations under different ship sizes (500 DWT and 3000 DWT) and collision speeds (2, 3, and 4 m/s) demonstrate that the proposed control strategy significantly reduces peak bow displacement by up to 19.94% and increases the output damping force, reaching over 70% of the impact load in some scenarios. Benchmark tests confirm the superior optimization performance of the TSO–DBO algorithm compared to several established algorithms. The proposed framework offers a practical, energy-efficient, and effective solution for mitigating ship–pier collision impacts, with strong potential for real-world engineering applications.