Holes Effects in Plane Periodic Multilayered Viscoelastic Media

• 作者: Emmanuel Siryabe Guy-Edgar Ntamack Pierre Maréchal
• 来源期刊: 声学期刊(英文)
• 学科: 医学
• 关键词: PERIODIC Structures HOLES POROSITY Phononic Crystal Forbidden BANDS Transmission Reflection ATTENUATION
• 年，卷（期）: 2013,（3）
• 页码范围: 80-87
• 页数: 8页
• 分类号: R73

摘要

This work deals with the study of the reflection and transmission properties of plane periodic structures composed of N periods (1 ≤ N ≤ 3) in the MHz frequency range. The period consists of two bounded plates presenting a high acoustic impedance contrast one of which is in aluminum, the other is in polyethylene. The longitudinal and transversal attenuations are considered in polyethylene and neglected in aluminum. We take into account the case of emerging holes in the polyethylene layer. Simulations are based on the stiffness matrix method (SMM) developed by Rokhlin. When attenuation is considered in polyethylene, the reflection coefficients are different depending on the insonification side. The comparison of results without or with holes configurations are performed and showed that throughout holes allow the rapid observation of forbidden bands. The attenuation of the whole multilayer is also determined.