Experimental Study on the Surface Applied Stress Measurement with Rayleigh Wave
超声瑞利波测试材料表面载荷应力的实验研究

In this paper, experimental study of material's surface stress measurement by using the propagation characteristics of ultrasonic Rayleigh wave is presented. In measuring process, sing-around method was adopted to test small velocity change caused by applied stress. A series of fixtures were designed to acquire the steady coupling and elastic contact between probe and specimen, which simplified the testing setup and improved the accuracy degree. Results indicate that the presence of applied stress causes a regular velocity change of Rayleigh wave propagating along parallel and perpendicular to the stress direction respectively. The slope of relative velocity change is abrupt in the case of smaller stress, and a good linear relationship between the relative velocity change and the applied stress is presented with increasing of stress. Based on the character of tested results, the data were fitted sector by sector to reduce the error of stress measurement.