An FEM Simulation for Guided Elastic Wave Generation and Reflection in Hollow Cylinders With Corrosion Defects

Abstract

The generation and reflection of guided elastic waves in hollow cylinders with corrosion defects have been investigated numerically for the purpose of nondestructive evaluation (NDE) of tubular structures. A new guided wave transducer model, time-delay periodic ring arrays (TDPRAs), has been used to generate the axisymmetric guided wave modes in hollow cylinders, and this is simulated by a finite element calculation. Unidirectional guided wave emission can be achieved by arranging a TDPRA’s parameters according to the principle of constructive and destructive interference. The guided wave reflections by axisymetric and nonaxisymmetric corrosion defects are analyzed using a 2-D and a 3-D FE simulation, respectively. The reflection features as well as mode conversion under the L(0,1) and L(0,2) mode incidences are discussed in association with the corrosion depth, the axial and circumferential extents in hollow cylinders.