Comparative study on vibration response test of buoyancy-core and rubber-core grid sandwich panels

  Objectives  To explore the influence of core materials on the vibration of composite grid sandwich panels,

  Methods  taking the panels as the research object, the vibration response of rubber-core grid sandwich panels and buoyancy-core grid sandwich panels under different conditions is compared by means of experiment, with emphasis given to the analysis of vibration suppression effect of core material on the two composite panels.

  Results  The results show that the mid-frequency and low-frequency(0-1 000 Hz) vibration response of the buoyancy-core grid sandwich panels in air is low, while the high-frequency(1 000-3 000 Hz) vibration response of the rubber-core grid sandwich panels is low. The influence of the factors such as the mass of the sandwich panel and the damping of the core on the vibration response of the panel is weakened due to the added mass effect and the added damping effect and the integral of the sandwich structure and the local bending stiffness of the panel are the main factors. The vibration response of the buoyancy-core grid sandwich panel within full-frequency band (0-3 000 Hz) is lower than that of the rubber-core grid sandwich panel.

  Conclusions  To reduce the vibration response of the panel, the core stiffness of the grid sandwich panel shall be close to the grid stiffness. In addition, the smaller the density and damping of the core, the greater the difference between the vibration response in air and water.