Ultrasonic testing of the stressed state of pipelines with consideration of the temperature factor

• Published in: Russian journal of nondestructive testing 2012-05, Vol.48 (5), p.272-276
• Main Authors: Nikitina, N. E., Kamyshev, A. V., Kazachek, S. V.
• Format: Article
• Language: English
• Subjects: Acoustic Methods; Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Structural Materials
• ISSN: 1061-8309; 1608-3385
• DOI: 10.1134/S1061830912050087

The effect of temperature changes on the estimation of biaxial stresses in pipelines by the acoustic method is considered. A method of using the acoustoelastic effect for the estimation of the uniaxial and biaxial stressed states using the changes in the propagation times of longitudinal and shear elastic waves along the normal to the surface of a pipe before and after changes in stress is described. Uniaxial stresses or the difference between biaxial stresses may be estimated by measuring mutually perpendicularly polarized shear wave delays, whose relative difference proportional to the stress value is temperature-independent. The algorithms for estimating the biaxial stresses incorporate parameters that are sensitive to the difference between the temperature dependences of the velocities of longitudinal and shear waves. Some experimental data on the estimation of the error of the method that were obtained at variable temperatures and the results of taking the temperature factor into account in the algorithms for estimating the stresses by the ultrasonic method are given.