Ultrasonic phased arrays have become widely used in recent years in non-destructive testing (NDT). However, most NDT arrays are 1-dimensional (1D), which generate 2-dimensional (2D) images from a single position and lack the ability to focus accurately through surfaces that are curved in multiple directions. In this paper, a 2D phased array is used to experimentally image artificial defects (represented by bottom-drilled holes and electrical discharge machined notches) within a test specimen with a doubly-curved surface profile in an immersion configuration. The array is mechanically scanned above the entire surface of the specimen and the 3-dimensional (3D), or volumetric, images generated at each position are combined to produce a single image of the specimen's entire surface. The surface profile is then extracted and discretised for interior volumetric imaging. The results show that the root mean square (RMS) error between the ultrasonically extracted surface and the true surface is 0.04 mm and 95% of absolute errors are less than 0.07 mm. Finally, the positions of visible defects are measured, using (i) the depth above the back wall and (ii) the lateral distance from a notch on the specimen's surface, and compared to their true values. The study shows that the standard deviation of depth and lateral position measurements is 0.68 mm and 0.89 mm respectively. Defects that are located beneath regions of sufficiently steep surface curvature were unable to be imaged.

近年来，超声波相控阵已在无损检测（NDT）中得到广泛使用。但是，大多数NDT阵列都是一维（1D）阵列，它们只能从一个位置生成二维（2D）图像，并且缺乏通过多个方向弯曲的曲面精确聚焦的能力。在本文中，二维相控阵被用于对浸没配置下具有双弯曲表面轮廓的试样中的人工缺陷（由底部钻孔和放电加工的缺口表示）进行实验成像。在样品的整个表面上方对阵列进行机械扫描，然后将在每个位置生成的3维（3D）图像或体积图像进行组合，以生成样品整个表面的单个图像。然后提取表面轮廓并离散化以进行内部体积成像。结果表明，超声提取的表面与真实表面之间的均方根（RMS）误差为0.04 mm，并且绝对误差的95％小于0.07 mm。最后，使用以下方法测量可见缺陷的位置：（i）后壁上方的深度和（ii）距试样表面上的凹槽的横向距离，并将其与真实值进行比较。研究表明，深度和横向位置测量的标准偏差分别为0.68 mm和0.89 mm。位于足够陡峭的表面曲率区域下方的缺陷无法成像。04毫米和95％的绝对误差小于0.07毫米。最后，使用以下方法测量可见缺陷的位置：（i）后壁上方的深度和（ii）距试样表面上的凹槽的横向距离，并将其与真实值进行比较。研究表明，深度和横向位置测量的标准偏差分别为0.68 mm和0.89 mm。位于足够陡峭的表面曲率区域下方的缺陷无法成像。04毫米和95％的绝对误差小于0.07毫米。最后，使用以下方法测量可见缺陷的位置：（i）后壁上方的深度和（ii）距试样表面上的凹槽的横向距离，并将其与真实值进行比较。研究表明，深度和横向位置测量的标准偏差分别为0.68 mm和0.89 mm。位于足够陡峭的表面曲率区域下方的缺陷无法成像。分别为89毫米。位于足够陡峭的表面曲率区域下方的缺陷无法成像。分别为89毫米。位于足够陡峭的表面曲率区域下方的缺陷无法成像。