Experimental Study on the Metal Material Surface Stress Measurement Using Surface Wave Technique
超声表面波检测金属材料表面应力的实验研究

In this paper,the relation between the surface wave propagation speed and the surface stress of a metal material is studied in theory and experiment.A formula for calculating the stress based on the surface wave acoustoelasticity is optimized.A pair of surface wave sensors with 5MHz in frequency is well prepared for the research.The flying-time difference between two ultrasonic echoes is calculated by application of the correlation method.Some experimental results of the flying-time difference under different surface stress are successfully demonstrated by a specimen made of A3 steel.Finally the effects of the roughness and flatness of specimen on the surface wave speed are carefully analyzed,and the methods for resolving the problem are verified by the experiment.