Research on attenuation factor of air-coupled ultrasonic testing

Major attenuator factor of air-coupled ultrasonic was analyzed. Finite difference time domain method was used to research transducer's pulse ultrasonic sound field characteristics and diffuse attenuator. Practical transducer's ultrasonic sound pressure distribution and far field region's distance attenuator characteristics were obtained by measuring experiments. Ultrasonic interface loss was analyzed according to transmission principal on air-solid interface, the relationship between oblique incidence angle and transmission ratio was acquired by numerical simulation and practice testing. Research results provide instruction to testing scheme and parameter selection of air-coupled ultrasonic testing.