Research on stress measurement and influencing factors of aero-engine duct assembly based on ultrasonic-guided wave method

The pipeline system plays a crucial role in the liquid gas transportation of the entire aero-engine, so the accurate measurement of pipeline assembly stress is significant to ensuring the safety of aero-engines. The measurement results of assembly stress in thin-walled ducts are affected by sensor spacing, temperature, medium in the ducts, the coupled and acoustic time difference algorithm. A measurement model of thin-walled duct assembly stress based on ultrasonic guided waves is established in this paper. The calibration and measurement system of thin-walled duct assembly stress is built. Then, the influence of various factors on the stress measurement results is theoretically simulated and analysed. Based on this, the optimal parameters of the measurement system are determined, and a compensation method is proposed to ensure the accuracy and reliability of the measurement results of thin-walled duct assembly stress. The experimental results show that the assembly stress coefficient is 2.01 MPa/ns, and the maximum measurement error of stress is 20.56 MPa. This study presents a novel method for accurately measuring the assembly stress of aero-engine thin-walled ducts.