Detection of stress corrosion cracks and other types of deterioration in pipes can be performed by producing elastic Lamb waves in the circumferential direction. Availability of Fiber Composite materials that have been utilized to retrofit the pipeline networks necessitates development of new theoretical procedures to analyze the behavior of anisotropic materials including Fiber Composites. The study of propagation of elastic waves in the circumferential direction for anisotropic materials primarily requires the derivation of dispersion curves. To obtain the dispersion curves, governing differential equations must be solved and the boundary conditions must be satisfied. Since differential equations for anisotropic materials are coupled, a general new analytical model is introduced which is capable of solving the coupled differential equations and removes the obstacle of decoupling which might not be always possible. To verify the validity of the new technique the results have been compared with the available data for isotropic materials and have matched satisfactorily. The proposed method can be extended to investigate pipe walls composed of several layers of isotropic and anisotropic materials and for problems with other types of geometry and boundary conditions.
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