Energy Streamlines and the Power Density Vector Accompanying Wave Excitation by a Piezoelectric Transducer in a Layered Phononic Crystal

This article presents the results of theoretical and experimental investigations of characteristic changes of Lamb wave excitation and scattering by a strip-like horizontal delamination in a layered elastic waveguide for Lamb waves induced by a piezoelectric wafer active sensor. The boundary integral equation method is used to describe wave propagation in an infinite layered waveguide with a delamination, while the frequency domain spectral element method is employed to model the dynamic behaviour of the piezoelectric wafer active sensor, which allows to simulate debonding between the piezoelectric wafer active sensor and the waveguide. Experimental investigations of the dynamic interaction of the piezoelectric wafer active sensor with a layered plate containing a horizontal delamination is conducted for several damage scenarios, showing a good agreement with the results obtained using the developed mathematical model. The obtained mathematical model is employed to analyse alteration of the piezo-induced Lamb waves including modes’ decomposition due to delamination. The conversion and/or conservation of the Lamb waves on account of a delamination is investigated. The electro-mechanical impedance of the piezoelectric transducer and the stress intensity factors of a delamination are analysed in dependence on the delamination location.

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Structural Optimization of a Piezoelectric Transducer for Selective Guided Wave Excitation

10.12783/shm2015/132 ◽

2015 ◽

Author(s):

MATEUSZ MISZCZYNSKI ◽

TADEUSZ STEPINSKI ◽

TADEUSZ UHL ◽

PAWEL PACKO

Keyword(s):

Structural Optimization ◽

Piezoelectric Transducer ◽

Guided Wave ◽

Wave Excitation

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Dramatic Enhancement of Elastic Wave Energy Harvesting Using a Gradient-Index Phononic Crystal Lens

Volume 2: Modeling, Simulation and Control; Bio-Inspired Smart Materials and Systems; Energy Harvesting ◽

10.1115/smasis2016-9264 ◽

2016 ◽

Cited By ~ 1

Author(s):

Serife Tol ◽

F. Levent Degertekin ◽

Alper Erturk

Keyword(s):

Energy Harvesting ◽

Plane Wave ◽

Elastic Wave ◽

Wave Energy ◽

Power Output ◽

Phononic Crystal ◽

Gradient Index ◽

Wave Band ◽

Wave Excitation ◽

Elastic Wave Energy

In this paper, we explore structure-borne elastic wave energy harvesting, both numerically and experimentally, by exploiting a Gradient-Index Phononic Crystal Lens (GRIN-PCL) structure. The proposed GRIN-PCL is formed by an array of blind holes with different diameters on an aluminum plate where the orientation and size of the blind holes are tailored to obtain a hyperbolic secant gradient distribution of refractive index guided by finite-element simulations of the lowest asymmetric mode Lamb wave band diagrams. Under plane wave excitation from a line source, experimentally measured wave field successfully validates the numerical simulation of wave focusing within the GRIN-PCL domain. A piezoelectric energy harvester disk located at the first focus of the GRIN-PCL yields an order of magnitude larger power output as compared to the baseline case of energy harvesting without the GRIN-PCL on the uniform plate counterpart for the same incident plane wave excitation. The power output is further improved by a factor of five using complex electrical load impedance matching through resistive-inductive loading as compared to purely resistive loading case.

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