Ultrasonic measurement of contact stress of tiny interference components

Tiny interference components are widely used in aerospace and instrumentation and other fields. The contact stress distribution is the key to evaluating the quality of interference joints, such as joint force, wear, and fatigue. In this study, ultrasonic waves were used to measure the stress distribution on the mating surface of interference components. The acoustic model is optimized based on statistical microcontact theory and virtual thin-layer theory. The reflection coefficient-contact stiffness mapping relationship is obtained by the optimized acoustic model. The contact stiffness-contact stress mapping relationship is obtained with the help of calibration experiments. Finally, the stress distribution of the mating surface of the interference components with two different structures was measured and compared with the theoretical results of the thick-walled cylinder theory. The comparison results show that the experimental results are in good agreement with the theoretical results. Therefore, this study provides an effective method for evaluating the connection quality of interference components.