Structural design and analysis of high-static-low-dynamic stiffness torsional vibration isolator for ship shafting

In order to isolate low-frequency torsional vibration for ship shafting, this paper proposes and analyzes a high-static-low-dynamic stiffness torsional vibration isolator.

First, the components are designed on the basis of the parallel connection of positive and negative torsional stiffness, and the isolator model is built using SolidWorks software and manufactured through 3D printing. The Duffing equation of the model is then solved by the harmonic balance method in order to study the influence of the structural parameters and excitation amplitude on the torque transmissibility of the isolator. Finally, finite element simulation is conducted on the model using Ansys Workbench software, and the printed prototype undergoes static load torsion test analysis.

The static test results show that the vibration isolator has high-static-low-dynamic stiffness characteristics within the range of −2° to 2°, and can bear torque of 150 N·mm. Torque transmissibility analysis verifies that the vibration isolator has better low-frequency performance with appropriate structural parameters than that of a linear isolator.

The proposed torsional vibration isolator achieves high-static-low-dynamic characteristics through the parallel connection of positive and negative stiffness, providing valuable references for low-frequency torsional control for ship shafting.