自聚焦线阵声场特征和检测应用  

Self-focusing Linear Array Sound Field Characteristics and Testing

作　　者：赵新玉[1] 闫浩明 张佳莹 ZHAO Xinyu;YAN Haoming;ZHANG Jiaying(School of Material Science and Engineering,Dalian Jiaotong University,Dalian 116028)

机构地区：[1]大连交通大学材料科学与工程学院,大连116028

出　　处：《机械工程学报》2020年第12期26-33,共8页Journal of Mechanical Engineering

基　　金：国家重点研发计划(2016YFF0203000);国家自然科学基金项目(51905070,51575134,51705484,51175113)资助项目。

摘　　要：相控阵超声技术近些年发展迅速,并被广泛应用于工业无损检测领域,但采用线阵换能器检测时,存在阵元长轴方向检测分辨力较差的问题。针对传统线阵换能器无法在阵元长轴方向聚焦的问题,提出采用自聚焦线阵换能器检测,可同时在阵元长轴和短轴方向获得较好检测分辨力。针对自聚焦线阵换能器声场计算方法和分布特征开展研究,发展了非近轴近似高斯声束叠加方法来计算自聚焦线阵辐射声场,为验证该方法的有效性,与瑞利积分数值方法进行精度和效率比较。进一步,利用上述理论方法来对比分析传统线阵和自聚焦线阵焦点强度、焦点尺寸和焦柱长度等参数随偏转角度变化的分布特征。对圆柱形工件进行检测,结果表明自聚焦线阵换能器可以检测出普通线阵换能器难以检测出轴向缺陷。理论和试验结果表明所提出的非近轴近似高斯声束叠加方法可以较准确地计算自聚焦线阵辐射声场,同时自聚焦线阵换能器对轴向和环向缺陷的检测灵敏度均较高。Phased array ultrasonic technology has been developed rapidly in recent years and is widely used in industrial non-destructive testing.However,resolution on the long axis of the element is poor when linear array is employed.The traditional linear array cannot be focused on the long axis of the element,in order to overcome such problem the self-focusing linear array is developed recently.Self-focusing linear array is used to focused on both short and long axis of the element to acquire high resolution.To calculate the sound field of the self-focusing line array,the non-paraxial approximation Gaussian sound beam superposition method is developed.Compared with Rayleigh integral numerical method,the effectiveness of the method is verified.Furthermore,those parameters(focus intensity,focal size,focal length,etc.)of both traditional and self-focusing linear array with the variational steering angle is investigated using the proposed calculation method.The cylindrical workpiece is detected with self-focusing linear array transducer and the linear array transducer.The results show that the self-focusing linear array transducer can detect that the linear array transducer is difficult to detect axial defects.It is seen from theoretical and experimental results that the sound field of the self-focusing line array is calculated precisely with the proposed non-paraxial approximation Gaussian sound beam superposition method.The sensitivity is high on both short and long axis of the element of self-focusing line array.

关 键 词：超声无损检测 自聚焦线阵 声场计算 高斯声束叠加 

分 类 号：TB553[理学—物理]