The Rayleigh wave excited by the electromagnetic acoustic transducer (EMAT) is an effective selection for surface plane stress measurement. However, the propagation velocity of Rayleigh wave on the metal surface is easily affected by the original rolling process. Besides, the direction of the plane stress state is usually unknown, which means that the propagation velocity cannot be expressed linearly by the stress. As a result, the traditional measurement model of one transmitter and one receiver can only realize the decouple of plane stress components by rotating method, which not only brings position error but also low measurement efficiency. Therefore, this paper focuses on a novel Rayleigh wave-EMAT for plane stress ultrasonic measurement. Firstly, the Rayleigh wave measurement model is established based on the acoustoelastic equation and displacement expression. Furthermore, an array Rayleigh wave-EMATintegrating three transmitters and three receivers is designed. Finally, the typical plane stress state of 5052 aluminum alloy plate after friction stir welding (FSW) is measured. The experimental results show good agreement compared with the hole-drilling method, which verifies the effectiveness of proposed method and designed EMAT.

由电磁声换能器 (EMAT) 激发的瑞利波是表面平面应力测量的有效选择。然而，瑞利波在金属表面的传播速度很容易受到原始轧制过程的影响。此外，平面应力状态的方向通常是未知的，这意味着传播速度不能用应力线性表示。因此，传统的一发一收测量模型只能通过旋转法实现平面应力分量的解耦，不仅带来位置误差，而且测量效率低。因此，本文重点研究一种用于平面应力超声测量的新型瑞利波 EMAT。第一，基于声弹性方程和位移表达式建立瑞利波测量模型。此外，还设计了一个集成了三个发射器和三个接收器的阵列瑞利波EMAT。最后，测量了搅拌摩擦焊（FSW）后5052铝合金板的典型平面应力状态。实验结果与钻孔方法相比具有良好的一致性，验证了所提方法和设计的EMAT的有效性。