Phased annular array transducers for omnidirectional guided wave mode control in isotropic plate like structures
Phased annular array transducers for omnidirectional guided wave mode control in isotropic plate like structures
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DOI：
10.1088/0964-1726/22/12/125022
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发表时间：
2013-11
影响因子：
4.1
通讯作者：
J. P. Koduru;Sepandarmaz Momeni;J. Rose
中科院分区：
文献类型：
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作者：
J. P. Koduru;Sepandarmaz Momeni;J. Rose
超声导波作为一种可靠的连续结构健康监测工具正在迅速崛起。它们的多模态性质沿着它们的长距离传播特性为询问结构提供了几种可能性。通常用于在结构中产生导波的换能器以任何频率激发多个模式;它们从缺陷和边界的复杂散射和反射通常使有用信息的提取复杂化。通常期望控制在结构中传播的导波模式以利用它们的独特性质用于不同的应用。导波模式控制的早期尝试涉及开发固定波长的线性和环形阵列换能器。它们唯一的缺点是换能器限于特定的波长，并且波长的变化需要换能器的变化。在本文中，我们提出了一种环形阵列换能器，可以产生模式控制的全向导波通过独立控制的阵列元件的振幅和相位的发展。假设一个简化的致动器模型，该模型将结构上的换能器负载近似为阵列元件下的恒定压力负载，并建立优化问题以计算元件的激励电压和相位。利用1-3型压电复合材料设计了一种五单元环形阵列换能器。通过激励A0和S 0导波模式，在铝板结构上对理论计算进行了实验验证。
Ultrasonic guided waves are fast emerging as a reliable tool for continuous structural health monitoring. Their multi-modal nature along with their long range propagation characteristics offer several possibilities for interrogating structures. Transducers commonly used to generate guided waves in structures excite multiple modes at any frequency; their complex scattering and reflection from defects and boundaries often complicates the extraction of useful information. Often it is desirable to control the guided wave modes propagating in a structure to take advantage of their unique properties for different applications. Earlier attempts at guided wave mode control involved developing fixed wavelength linear and annular array transducers. Their only disadvantage is that the transducer is limited to a particular wavelength and a change in wavelength necessitates a change in the transducer. In this paper, we propose the development of an annular array transducer that can generate mode controlled omnidirectional guided waves by independently controlling the amplitude and phase of the array elements. A simplified actuator model that approximates the transducer loading on the structure to a constant pressure load under the array elements is assumed and an optimization problem is set up to compute the excitation voltage and phase of the elements. A five element annular array transducer is designed utilizing 1–3 type piezocomposite materials. The theoretical computations are experimentally verified on an aluminum plate like structure by exciting A0 and S0 guided wave modes.