Micro-energy dissipation and vibration reduction properties of metal-fiber composite structures under thin plate constraints

To suppress the vibration response of load-bearing structure in underwater vehicles, this study proposes a thin-plate and metal-fiber composite structure (TPMF). A validated finite element model is developed to investigate the enhancement mechanism of thin-plate constraints on the energy dissipation characteristics of metal fibers, along with the associated parametric regulation laws. By introducing the energy dissipation concentration factor (EDCF) and inefficient frequency points (IFPs) as microscopic evaluation metrics, the internal energy dissipation behavior of the composite is characterized in depth. The results reveal that the high stiffness of the thin plate effectively reconfigures the deformation mode of the metal fibers, transitioning it from inefficient bending to intensive transverse shearing. Comparative analysis of shear strain and power dissipation density contours across varying plate thicknesses elucidates the evolutionary logic of energy dissipation, transforming from localized deficits to global saturation. Experimental results confirm that the optimized TPMF outperforms bare metal fiber structures across a broad frequency band (0–5000 Hz), achieving an average vibration level difference 5.49 dB higher than the bare configuration, a 20.77% enhancement in damping efficiency. This study clarifies the shear-enhancement mechanism under structural constraints and provides critical engineering guidance for the design of high-performance damping systems.