圆柱类构件超声相控阵聚焦模型

在利用平面相控阵超声换能器对圆柱类构件检测时，受曲界面结构引起的入射波和回波时延的影响，扫描声束的波阵面产生弯曲，在利用传统迭代遍历算法计算延迟时间时效率低，无法发挥相控阵换能器检测优势。针对上述问题，建立了一种基于圆柱类构件特征和耦合介质特性的超声相控阵扫描成像的聚焦模型。该模型基于换能器、耦合介质、圆柱类构件材料特性和几何关系以及声线模型和折射定律，建立了耦合介质及被检构件的声速、曲面曲率半径、阵列与曲面间的距离等关联的延迟时间聚焦控制模型。利用该模型计算出的延时时间，对各阵元发射时间进行控制，从而实现扫描声束的聚焦。该文以液体和有机玻璃制介质楔块为例，对圆柱钢曲面的相控阵声束聚焦进行了仿真实验，结果表明该文方法计算效率显著提升，同时声束可以在预设位置实现聚焦，验证了该模型在计算效率上的优势与有效性。

The ultrasonic phased array focusing model of cylindrical component

When planar phased array ultrasonic transducer is used to detect cylindrical components, the wave front of the scanned acoustic beam is bent due to the impact of incident wave and echo delay caused by the curved interface structure. The traditional iterative traversal algorithm has low efficiency and accuracy error in calculating the delay time, so it can not give full play to the advantages of phased array transducer. Aiming at the above problems, a focusing model of ultrasonic phased array scanning imaging based on the characteristics of cylindrical components and coupled media is established in this paper. Based on the material properties and geometric relations of transducer, coupling medium, cylindrical component, sound model and refraction law, the delay time focusing control model is established to correlate the sound velocity, curvature radius of surface, distance between array and surface of the coupling medium and the component under test. The delay time calculated by the model is used to control the emission time of each array, so as to realize the focus of the scanning sound beam. This paper takes liquid and plexiglass wedges as examples to simulate the phased array beam focusing of cylindrical steel surfaces. The results show that the computational efficiency of the proposed method is significantly improved, and the beam can be focused at a preset position, which verifies the advantages and effectiveness of the proposed model in computational efficiency.