Tuning method of phononic band gaps of locally resonant pentamode metamaterials

The method for tuning the first phononic band gaps (PGBs) of locally resonant pentamode metamaterials (PMs) is proposed in this paper. Based on the equivalent relationship between the locally resonant mode at the lower edge of the first PBGs and spring-mass system, the approximate relationships between the lower edge of the first PBGs and structure parameters are obtained. The theoretical and numerical results show that the first phononic band gaps of PMs can be tailored between 52 Hz and 548 Hz by a small-sized PMs. In addition, the single mode PBGs of PMs can be expanded by 6.5 times, and the pentamodal characteristics can be improved by 13.7 times.