School of Mechanical Engineering, Yonsei University, Seoul 120-749, Korea.
J Acoust Soc Am. 2011 Nov;130(5):2720-7. doi: 10.1121/1.3643828.
Despite its introduction more than a decade ago, a two-dimensional ultrasonic array remains a luxury in nondestructive evaluation because of the complexity and cost associated with its fabrication and operation. This paper describes the construction and performance of a two-dimensional virtual array that solves these problems. The virtual array consists of only two transducers (one each for transmit and receive) and an aluminum chaotic cavity, augmented by a 10 × 10 matrix array of rectangular rods. Each rod, serving as an elastic waveguide, is calibrated to emit a collimated pulsed sound beam centered at 2.5 MHz using the reciprocal time reversal. The resulting virtual array is capable of pulse-echo interrogation of a solid sample in direct contact along 10 × 10 scan lines. Three-dimensional imaging of an aluminum test piece, the nominal thickness of which is in the order of 1 cm, is successfully carried out using the virtual array.
尽管二维超声阵列在十多年前就已经问世，但由于其制造和操作的复杂性和成本，它仍然是无损评估中的一种奢侈品。本文介绍了一种二维虚拟阵列的构建和性能，该阵列解决了这些问题。虚拟阵列仅由两个换能器（一个用于发射，一个用于接收）和一个铝制混沌腔组成，并通过 10×10 矩阵的矩形棒组成。每个棒作为弹性波导，使用互易时间反转进行校准，以在 2.5 MHz 处发射聚焦脉冲声波束。由此产生的虚拟阵列能够沿 10×10 条扫描线对直接接触的固体样品进行脉冲回波检测。使用虚拟阵列成功地对厚度约为 1 厘米的铝试件进行了三维成像。
