Effect of an internal open crack on pipes wave propagation

摘要

Stress guided waves in the sonic and ultrasonic regime are acknowledged as a powerful tool to inspect pipes in a non-invasive manner. A key point of the inspection procedure is related to the dispersive behavior of guided waves, that for a given pipe is defined by the so-called dispersion curves. Such behavior, is generally predicted by means of analytical formulations. However, when the geometry of the pipe cross-section is not axially symmetric, such as in the presence of an open internal crack running along the pipe length, analytical formulations fail. Here, the computation of the guided waves properties for such a scenario is addressed via a Semi Analytical Finite Element (SAFE) formulation in which the open crack is modeled at the mesh level. Different crack depths are considered and their effect on the waves dispersion curves are highlighted. The results could be of interest in pipeline inspection and monitoring.