Isolating low-frequency vibration from power systems on a ship using spiral phononic crystals

摘要

There is increasing concern that the locally resonant phononic crystals (LRPCs) are used to reduce low-frequency noise and vibration in ship and ocean engineering. In this work, the vertical velocity amplitude spectrums in "ChangJing 9'' are measured following the ISO international standards. According to the low-frequency mechanical vibration generated by the power systems on the ship, a single-phase spiral-shaped phononic crystal is designed and analyzed based on the locally resonant modes. The vibration characteristics of the phononic crystal plates with different boundary conditions and loads are numerically simulated, and groups of experimental tests are conducted to verify the abilities of vibration isolation for three kinds of phononic crystals. Furthermore, a vibration isolation platform installed on a steel plate is also studied by numerical simulations and experiments. The results show that the spiral phononic crystal has good adaptability for a wide range of low-frequency band, around 15-45 Hz, by altering the cylinders conveniently. The LRPC has a potential application to isolate vibration for protecting electronic devices and precision instruments despite the complex vibration sources and boundaries on the ship. In short, this work is an active exploration of putting the LRPCs into the field of ship vibration and noise control.