Automatic Measurement of Contact Stress and Connection Force of Interference Components by Ultrasound

Tiny interference components are crucial in the precision of Marine machinery. Contact stress and connection force are important factors to evaluate the quality of interference components. In this article, the ultrasonic method is used to measure the stress distribution and the connection force on the mating surface of interference components. The acoustic model is optimized to some extent by analyzing statistical micro-contact theory and virtual thin layer theory. On the basis of the above, we can get the reflection coefficient-contact stiffness mapping relationship. The contact stiffness contact stress mapping relationship is obtained with the help of calibration experiments. Then the stress distribution on the mating surface of interference components with two different structures, namely the uniform cylinder and the step cylinder, is measured and compared with the theoretical results of the thick-walled cylinder theory. The experimental results are in good agreement with the theoretical results. Finally, based on the measurement results of stress distribution, the connection force is calculated and compared with the connection force measured by the press-out experiment. The results show that the ultrasonic stress measurement method can accurately measure the connection force of interference components, and the relative error is within 20%. Therefore, this article can provide a better method for the quality analysis of interference components.