Wide-range control of impulse transmission by cylindrical shell chains with varying aspect ratios

Abstract

The ability to control wave propagation for impulse transmission in a wide range is desired. A novel structure, i.e. a cylindrical shell chain with varying aspect ratio, was proposed to design new waveform control systems. The chains can offer superior control of elastic wave propagation, including waveform attenuation and amplification. Nonlinear wave propagation in the chains was studied numerically, analytically and experimentally. The wave propagation in the chain with a positive/negative aspect ratio gradient (aspect ratio increasing/decreasing along the loading direction) was examined. It is found that the chain with a positive aspect ratio gradient amplifies the forces in wave propagation due to the dramatic increase in the apparent elastic modulus along the impact direction, whereas the chain with a negative aspect ratio gradient shows the opposite. The theoretical results are consistent with the data obtained from the corresponding numerical simulations and experimental tests. The transmitted peak force increases with the aspect ratio distribution parameters. Compared with density gradient chains, the aspect ratio gradient chains proposed in this study could control the transmitted impulse in a wider range. This study can be helpful to improve the design of waveform control systems for amplifying/attenuating impact impulses.