Lightweight-broadband vibration reduction for marine crankcases with customized nonlinear damping metamaterials

The vibration reduction capacity of linear metamaterials is inherently constrained by implementation costs, such as limited additional mass ratios and restricted installation space. Nonlinear damping metamaterials (NDMs), leveraging their distinctive nonlinear excitation–damping mechanism, provide a pathway to overcome the cost–benefit limitations in vibration reduction design. However, conventional design methods cannot fully release the dissipation potential of NDMs, which makes lightweight vibration reduction highly challenging. To this end, this paper proposes a layout regulation strategy that integrates Particle Swarm Optimization (PSO) with COMSOL–MATLAB co-simulation to optimize aperiodic NDMs, thereby maximizing dissipation capacity through targeted layout regulation. Moreover, motivated by the vibration reduction requirements of marine crankcases, we investigate the energy regulation mechanism and performance optimization of NDMs through a “Modeling–Target Setting–Structural Design–Testing–Optimization” framework. Experimental and numerical results reveal that an NDMs cell achieves nearly 40% average vibration attenuation with only 0.2% additional mass ratio. Furthermore, the multi-cell of NDMs delivers significant enhanced damping capacity and bandgap broadening. Unlike conventional strategies, this work establishes a layout regulation paradigm for improving the damping efficiency of metamaterials, providing practical insights into scenarios that demand a balance between vibration mitigation and implementation cost.