In this paper, modal analysis is carried out by using a Frenet frame-based shape measurement algorithm. This algorithm is validated through experiments conducted with a long slender, aluminum cantilever structure (65.625′′×2.0′′×0.125′′), which is instrumented with eight serially multiplexed fiber Bragg grating (FBG) sensors. The multiplexed FBG sensors measure the bending strain distribution a...

Abstract—Radiation characteristics of a probe-excited rectangular ring antenna are investigated by using the dyadic Green’s function approach. The radiation characteristics, such as radiation pattern, beam-peak direction, half-power beamwidth and directivity, are analyzed. For the specified operating frequency, the ring width and ring height are selected as the same cross-sectional dimension of...

Modal control and spatial filtering technologies for vibration and/or structural acoustics radiation mitigation may be implemented through the use of distributed modal piezoelectric transducers with properly shaped electrodes which, in order to increase the robustness and stability of the controlled structural system, turn undesirable mode’s contributions unobservable and uncontrollable over th...

An experimental technique is being developed for mapping the normal mode field and its wavenumber spectrum as a function of position in a complex, shallow-water waveguide environment whose acoustic properties vary in three spatial dimensions. By describing the spatially varying spectral content of the modal field, the method provides a direct measure of the propagation characteristics of the wa...

In this paper, natural frequency and response of forced vibration of composite laminated conical shells under different boundary conditions are investigated. To this end, equations of Donnell's thin shell theory are used as governing equations. The analytical Galerkin method together with beam mode shapes as weighting functions is employed to solve the problem. Due to importance of boundary con...

Special approaches unique to the waveband are required for the modelling of terahertz optical systems. Ray tracing is inadequate because in typical instruments the propagating beams are not very many wavelengths in diameter and a "quasi-optical" approach is required in which Fresnel diffraction effects can be efficiently and accurately simulated. Typically, it is also necessary to be able to si...