Axisymmetric Guided Waves in Jointed Laminated Cylinders

Abstract

A combination of finite element formulation and wave function expansion is used to investigate the scattering of axisymmetric guided waves by an interphase region with bonding material between two laminated cylinders. The motivation of this study is to develop an effective numerical technique to characterize the material properties and the thickness of the bond region between two cylinders that are laminated and anisotropic. Numerical results of wave scattering are presented for a welded steel pipe with different weldment shapes and for two cross-ply symmetrically laminated composite cylinders that are bonded end to end. It is shown that as the frequency increases the reflection coefficients have resonance peaks while the transmission coefficients have sharp drops at the cutoff frequencies of higher guided modes in the cylinders. The resonance peaks of reflection coefficients become increasingly pronounced as the thickness of the joint increases. Another interesting feature is that the reflection coefficients have minimums at frequencies that depend on the thickness and the material properties of the joint. These features may be useful in quantitative nondestructive evaluation of joint properties.