Lamb waves
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Surface Acoustic Wave (SAW) Sensors: Physics, Materials, and Applications Open
Surface acoustic waves (SAWs) are the guided waves that propagate along the top surface of a material with wave vectors orthogonal to the normal direction to the surface. Based on these waves, SAW sensors are conceptualized by employing pi…
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Elastic pseudospin transport for integratable topological phononic circuits Open
Precise control of solid-state elastic waves’ mode content and coherence is of great use nowadays in reinforcing mechanical energy harvesting/storage, nondestructive material testing, wave-matter interaction, high sensitivity sensing, and …
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Seismic metasurfaces: Sub-wavelength resonators and Rayleigh wave interaction Open
We consider the canonical problem of an array of rods, which act as resonators, placed on an elastic substrate; the substrate being either a thin elastic plate or an elastic half-space. In both cases the flexural plate, or Rayleigh surface…
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Graded elastic metasurface for enhanced energy harvesting Open
In elastic wave systems, combining the powerful concepts of resonance and spatial grading within structured surface arrays enable resonant metasurfaces to exhibit broadband wave trapping, mode conversion from surface (Rayleigh) waves to bu…
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Structural Health Monitoring system based on a concept of Lamb wave focusing by the piezoelectric array Open
Piezoelectric transducer arrays are utilized in Structural Health Monitoring systems as a means for excitation and sensing of elastic waves. Anomalies of propagating waves have enabled to develop damage detection algorithms. Depending on a…
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Nonlinear ultrasonic guided waves—Principles for nondestructive evaluation Open
Research into the use of nonlinear ultrasonic guided waves for nondestructive evaluation is expanding at a high rate because of the great potential benefit that they possess for early detection of material degradation. However, development…
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4.5 GHz Lithium Niobate MEMS Filters With 10% Fractional Bandwidth for 5G Front-Ends Open
This paper presents a new class of micro-electro-mechanical system (MEMS) C-band filters for 5G front-ends. The filter is comprised of resonators based on the first-order asymmetric Lamb wave (A1) mode in thin-film lithium niobate. Two fil…
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High sensitivity flexible Lamb-wave humidity sensors with a graphene oxide sensing layer Open
This paper reports high performance flexible Lamb wave sensors with a graphene oxide sensing layer.
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High frequency guided ultrasonic waves for hidden fatigue crack growth monitoring in multi-layer model aerospace structures Open
Especially for ageing aircraft the development of fatigue cracks at fastener holes due to stress concentration and varying loading conditions constitutes a significant maintenance problem. High frequency guided waves offer a potential comp…
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A data-driven temperature compensation approach for Structural Health Monitoring using Lamb waves Open
This paper presents a temperature compensation method for Lamb wave structural health monitoring. The proposed approach considers a representation of the piezo-sensor signal through its Hilbert transform that allows one to extract the ampl…
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Nonlinear ultrasonic detection for evaluating fatigue crack in metal plate Open
In engineering structures, metal materials always endure fatigue cracks under long-term service. There has been a demand for developing a structural health monitoring method to evaluate micro-sized fatigue cracks, as cracking is considered…
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Baseline-free delamination inspection in composite plates by synthesizing non-contact air-coupled Lamb wave scan method and virtual time reversal algorithm Open
In the paper, we combined air-coupled Lamb wave scan method and virtual time reversal (VTR) algorithm and proposed a composite baseline-free delamination inspection technique of composite plates. According to VTR algorithm, time reversal p…
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Fatigue crack detection in pipes with multiple mode nonlinear guided waves Open
This study elaborates fundamental differences in fatigue crack detection using nonlinear guided waves between plate and pipe structures and provides an effective approach for analysing nonlinearity in pipe structures. For this purpose, gui…
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Enabling Higher Order Lamb Wave Acoustic Devices With Complementarily Oriented Piezoelectric Thin Films Open
In this work, we present a new paradigm for enabling gigahertz higher-order Lamb wave acoustic devices using complementarily oriented piezoelectric (COP) thin films. Acoustic characteristics are first theoretically explored with COP lithiu…
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Guided wave temperature correction methods in structural health monitoring Open
In this article, a method for addressing temperature effects using Lamb waves is developed with application to baseline comparison damage detection. The proposed method is based on baseline signal stretch with an improved minimum residual …
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Numerical and experimental investigation of nonlinear ultrasonic Lamb waves at low frequency Open
Nonlinear ultrasonic Lamb waves are popular to characterize the nonlinearity of materials. However, the widely used nonlinear Lamb mode suffers from two associated complications: inherent dispersive and multimode natures. To overcome these…
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Elastic metamaterial-based seismic shield for both Lamb and surface waves Open
Controlling the propagation of seismic waves to protect critical infrastructure via metamaterial is of new topical interest. This approach can be implemented by remote shielding of incoming waves rather than with vibration isolating struct…
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Designing 3D Digital Metamaterial for Elastic Waves: From Elastic Wave Polarizer to Vibration Control Open
Elastic wave polarizers, which can filter out linearly polarized elastic waves from hybrid elastic waves, remain a challenge since elastic waves contain both transverse and longitudinal natures. Here, a tunable, digital, locally resonant m…
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Inverse characterization of plates using zero group velocity Lamb modes Open
In the presented work, the characterization of plates using zero group velocity Lamb modes is discussed. First, analytical expressions are shown for the determination of the k-ω location of the zero group velocity Lamb modes as a function …
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Nonlinear guided wave propagation in prestressed plates Open
The measurement of stress in a structure presents considerable interest in many fields of engineering. In this paper, the diagnostic potential of nonlinear elastic guided waves in a prestressed plate is investigated. To do so, an analytica…
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High $Q$ Antisymmetric Mode Lithium Niobate MEMS Resonators With Spurious Mitigation Open
This paper reports on the demonstrations of first-order antisymmetric Lamb wave (A1) mode resonator as a new platform for front-end filtering of the fifth-generation (5G) wireless communication. The sub-6 GHz resonance in this work is achi…
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Structural Health Monitoring Using Lamb Wave Reflections and Total Focusing Method for Image Reconstruction Open
This investigation aimed to adapt the total focusing method (TFM) algorithm (originated from the synthetic aperture focusing technique in digital signal processing) to accommodate a circular array of piezoelectric sensors (PZT) and charact…
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Machine Learning-Enriched Lamb Wave Approaches for Automated Damage Detection Open
Lamb wave approaches have been accepted as efficiently non-destructive evaluations in structural health monitoring for identifying damage in different states. Despite significant efforts in signal process of Lamb waves, physics-based predi…
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Full wavefield processing by using FCN for delamination detection Open
A novel full wavefield processing method by using fully convolutional neural networks is presented. The full wavefield of propagating Lamb waves in the fibre-reinforced composite plate was simulated by the parallel spectral element method.…
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Lamb waves-based technologies for structural health monitoring of composite structures for aircraft applications Open
The most common researched area of damage in a composite material such as carbon fibre reinforced plastics (CFRP) used currently in aircraft construction is barely visible impact damage (BVID), significantly reducing mechanical properties.…
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Excitation of fundamental shear horizontal wave by using face-shear (d36) piezoelectric ceramics Open
The fundamental shear horizontal (SH0) wave in plate-like structures is extremely useful for non-destructive testing (NDT) and structural health monitoring (SHM) as it is non-dispersive. However, currently, the SH0 wave is usually excited …
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DeepSHM: a deep learning approach for structural health monitoring based on guided Lamb wave technique Open
In our previous work, we demonstrated how to use inductive bias to infuse a convolutional neural network (CNN) with domain knowledge from fatigue analysis for aircraft visual NDE. We extend this concept to SHM and therefore in this paper, …
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Evaluation of disbonds at various interfaces of adhesively bonded aluminum plates using all-optical excitation and detection of zero-group velocity Lamb waves Open
Inspection of adhesively bonded metallic plates, commonly used in aircraft structures, remains challenging for modern non-destructive testing (NDT) techniques. When a probing ultrasound (US) wave interacts with the plate boundaries, it pro…
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Implication of changing loading conditions on structural health monitoring utilising guided waves Open
Structural health monitoring systems based on guided waves typically utilise a network of embedded or permanently attached sensors, allowing for the continuous detection of damage remote from a sensor location. The presence of damage is of…
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Lamb Wave-Based Structural Health Monitoring on Composite Bolted Joints under Tensile Load Open
Online and offline monitoring of composite bolted joints under tensile load were investigated using piezoelectric transducers. The relationships between Lamb wave signals, pre-tightening force, the applied tensile load, as well as the fail…