Ultrasonic stress measurement technique based on shear wave birefringence considering temperature effects

Addressing the problem that the stress detection accuracy based on the shear wave birefringence method is greatly affected by temperature, a shear wave birefringence ultrasonic stress measurement technique considering temperature influence was proposed. First, based on the acoustoelastic effect, a stress calculation model for the shear wave birefringence method including a temperature correction term was theoretically derived, and a temperature correction coefficient was introduced to correct the ultrasonic propagation time. Then, based on tensile calibration tests, the stress coefficient and temperature correction coefficient for 6061 aluminum alloy were calibrated, and the measurement accuracy of the proposed method was verified at different temperatures. The experimental results showed that in a variable temperature environment, the stress detection error of the proposed method ranged from 2.29% to 10.82%, with test errors in the high stress region （50-90 MPa） reduced to within 3.5%, and measurement accuracy improved by approximately 13% compared to the uncorrected method.