Ultrasonic Measurement of Stress Distribution and Connection Force Prediction for Interference Fit

In order to realize the measurement of stress distribution and the prediction of connection force of interference fit, an ultrasonic measurement system and calibration device were established based on the principle of ultrasonic pulse reflection method. Firstly, the influencing factors of the reflection coefficient were analyzed by the calibration device. Then, the stress distribution of three types of interference (6μm, 12μm, and 18μm) was measured by the ultrasonic measuring system, and the connection force was predicted based on the measurement results. Finally, the prediction results were verified by extrusion experiments. The research indicates that couplant, the size and texture direction of roughness, and covered boundary are the key factors affecting the measurement accuracy. The error analysis model of the covered boundary can realize the prediction and compensation of measurement error. The measured stress distribution can effectively reflect the contact state and defects between the mating surfaces, and the relative error of the connection force is less than 16%. Therefore, the analytical method and measuring device established in this paper can achieve accurate measurement of stress distribution and reliable prediction of connection force, which provides technical support for reliable evaluation of the connection quality of interference fit. In addition, the research methods in this paper have universal applicability, and it is of great significance to achieve the measurement of stress between different mating surfaces. © 2019, Editorial Department of Journal of Propulsion Technology. All right reserved.