Analysis of Wave Propagation in Tunable Auxetic Star-shaped Honeycombs

• Main Authors: Wei-DiChou, 周椲迪
• Other Authors: Lien-Wen Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/33036775964464901007

碩士 === 國立成功大學 === 機械工程學系 === 104 === The development of star-shaped honeycombs filled with matrix in the void area is presented. Divide into two parts, the different matrix be filled and the different area be filled. The effects of the matrix on the effective constants such as Poisson’s ratio, Young’s modulus, and shear modulus are investigated and discussed. Then the wave propagation of star-shaped honeycombs filled with matrix are investigated, and the outside-filled star-shaped honeycombs exhibit collimate phenomenon in certain frequency. In order to design phononic crystals device, we proposed a tunable piezoelectric materials which is connected to a separate negative capacitance circuit. Making use of the characteristic which change the effective modulus by tuning the variable resistor in the circuit, we introduce piezoelectric materials into star-shaped honeycombs. The phononic bandgap depends on the tunable effective modulus, giving rise to prospective applications such as elastic/acoustic filters and sonic switch. The performance obtained by COMSOL Multiphysics Finite Element simulations confirmed the feasibility of the sonic devices proposed.