Abstract: In this paper, to attenuate the elastic wave, a new type of sandwich structure with a four-ligament chiral structure as the core and carbon fiber composite material as the panel is proposed. Firstly, based on Bloch’s theorem and COMSOL finite element software, the vibration bandgap of the four-ligament chiral structure is solved; secondly, the influence of the filling materials of the nodes of the protocell and the geometrical parameters on the vibration bandgap of the chiral structure are analyzed; thirdly, the transmission characteristics of the waves within the four-ligament chiral sandwich structure are investigated in the frequency domain; and lastly, the experiments on the vibration transmission and attenuation characteristics of the four-ligament chiral sandwich structure are carried out. The study shows that: the chiral structure node filling material can produce a low-frequency bandgap, and the geometric parameters have a great influence on the bandgap, by adjusting the geometric parameters, the bandgap can be made to be in the low-frequency region; when the vibration frequency is in the range of the bandgap, the chiral structure has a good attenuation characteristic. These findings will guide the application of four-ligament chiral sandwich structures in engineering.

Key words: four-ligament chiral structure, carbon fibre reinforced plastics, sandwich structure, vibration band gap, geometric parameters