3.相控阵成像的基本原理 Basics of Phased Array Imaging

显示全部楼层 · 2015-1-12 21:10:31

常规超声仪器和相控阵超声仪器都使用高频声波，核查被测样件的内部结构或测量样件的厚度。它们都以物理学中支配声波传播的相同的基本法则为基础。这两种超声技术都使用相似的概念表示超声数据。

Both conventional and phased array ultrasonic instruments utilize high-frequency sound waves to check the internal structure of a test piece or measure its thickness. They both rely on the same basic laws of physics that govern sound wave propagation. Similar concepts are employed in both ultrasonic technologies to present ultrasonic data.

而相控阵仪器由于要为带有16个晶片到256个晶片的探头提供脉冲激励的方式（聚焦法则），一般来说都具有多通道性能。与常规探伤仪不同的是，相控阵系统可以使来自一个探头的声波以多种不同的折射角度进行扫查，或沿线性声程进行扫查，还可以使声波在一系列不同的深度位置上动态聚焦，从而增强了检测设置的灵活性和性能。

Phased array instruments, on the other hand, are naturally multichanneled as they need to provide excitation patters(focal laws) to probes with 16 to as many as 256 elements. Unlike conventional flaw detectors, phased array systems can sweep a sound beam from one probe through a range of refracted angles, along a linear path, or dynamically focus at a number of different depth, thus increasing both flexibility and capability in inspection setups.

相控阵成像的特性可以使用户观察到相对的点对点的变化以及多角度的缺陷响应，从而有助于缺陷的辨别与定量。这种技术本身从表面上看似乎极具复杂性，但它无需使用常规UT检测方法经常需要使用的复杂的支架与多个探头，从而在实际上不仅简化了扩大检测覆盖区域的过程，而且还提高了检测的性能。

Phased array imaging provides the user with the ability to see relative point-to-point changes and multiangular defect responses, which can assist in flaw discrimination and sizing. While this can seem inherently complex,it can actually simplify expanding inspection coverage with increased detection by eliminating the complex fixtures and multiple transducer that are often required with conventional UT inspection methods.