Guided wave propagation and scattering in pipeworks comprising elbows: Theoretical and experimental results

13th Anglo-French Physical Acoustics Conference

El Bakkali, M.^1 ; Lhémery, A.^1 ; Baronian, V.^1 ; Chapuis, B.^1

CEA, LIST, Gif-sur-Yvette

F- 91191, France^1

关键词: Curvilinear coordinate;    Elastic guided waves;    Mode matching method;    Numerical predictions;    Propagation matrix;    Scattering matrices;    Scattering phenomenon;    Semianalytic finite-element method;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/581/1/012011/pdf
DOI  :  10.1088/1742-6596/581/1/012011

来源: IOP

【 摘 要 】

Elastic guided waves (GW) are used to inspect pipeworks in various industries. Modelling tools for simulating GW inspection are necessary to understand complex scattering phenomena occurring at specific features (welds, elbows, junctions...). In pipeworks, straight pipes coexist with elbows. GW propagation in the former cases is well-known, but is less documented in the latter. Their scattering at junction of straight and curved pipes constitutes a complex phenomenon. When a curved part is joined to two straight parts, these phenomena couple and give rise to even more complex wave structures. In a previous work, the SemiAnalytic Finite Element method extended to curvilinear coordinates was used to handle GW propagation in elbows, combined with a mode matching method to predict their scattering at the junction with a straight pipe. Here, a pipework comprising an arbitrary number of elbows of finite length and of different curvature linking straight pipes is considered. A modal scattering matrix is built by cascading local scattering and propagation matrices. The overall formulation only requires meshing the pipe section to compute both the modal solutions and the integrals resulting from the mode-matching method for computing local scattering matrices. Numerical predictions using this approach are studied and compared to experiments.