  In this paper, we explore the concept of structural Luneburg Lens (SLL) as a
design framework for performing dynamic structural tailoring to obtain a
structural wave cloak and a structural waveguide. The SLL is a graded
refractive index lens, which is realized by using a variable thickness
structure defined in a thin plate. Due to the thickness variation of the plate,
the refractive index decreases radially from the centre to the outer surface of
the lens. By taking advantage of the unique capabilities of SLL for flexural
wave focusing and collimation, we develop a structural wave cloak and waveguide
based on cascaded SLLs. The cascaded SLL design enables the integration of
functional devices into thin-walled structures while preserving the structural
characteristics. Analytical, numerical, and experimental studies are carried
out to characterize the performance of the SLL cloak and the SLL waveguide. The
results demonstrate that that these cascaded SLL devices exhibit excellent
performance for structural wave cloaking and waveguiding over a broadband
operating frequency range.
