Forming Band Gaps in Shocked Periodic Structures

Abstract

There are many situations in which shock transmission must be suppressed in the use of machinery, such as the protection of internal structures from shocks to which the product is subjected and the transmission of shocks due to the operation of internal mechanisms. There have been cases where rubber has been used in structures to absorb vibration, such as mounts used in machines, but there are also cases where rigidity is required. In this study, a 3D printer is used to create a structure with periodically arranged three-dimensional objects with different stress transfer characteristics, such as different cross-sectional areas, and the frequency response characteristics of the created structure are investigated. The power spectrum, coherence function, and transfer function of each specimen are measured by impact test, and evaluated by the transfer function. As a result of the experiment, it was confirmed that a band gap was generated in the periodic structure. It was also found that the bandgap frequency band shifted to lower frequencies as the number of steps in the periodic structure was increased.