Application of Piezo Sensors in EMI and Guided Wave Techniques

2013 ◽  
Vol 569-570 ◽  
pp. 702-709
Author(s):  
Pawel Malinowski ◽  
Lukasz Skarbek ◽  
Wieslaw Ostachowicz
Keyword(s):  
Wave Propagation ◽  
Laser Scanning ◽  
Guided Waves ◽  
Damage Index ◽  
Piezoelectric Sensor ◽  
Guided Wave ◽  
Structural Element ◽  
Electromechanical Impedance ◽  
Impedance Characteristics ◽  
Narrowband Signal

In reported research piezoelectric sensors were used for damage identicitaion purposes. Piezoelectric sensor was used for specimen excitation. Two techniques were investigated. The Electromechanical impedance (EMI) technique and guided wave based technique. The principle of EMI technique is based on measurement and analysis of impedance of piezoelectric transducers bonded on or embedded in investigated structure. It is assumed that structural change should influence the impedance characteristics of the transducers. The guided wave based technique is based on the guided elastic wave propagation phenomena. This type of waves can be used in order to obtain information about structure condition and possibly damaged areas. In reported investigation piezoelectric sensor was used to excite guided waves in chosen structural element. Dispersive nature of guided waves results in changes of velocity with the wave frequency, therefore a narrowband signal was used to minimize the dispersion phenomenon. The generated signal was amplified before applying it to the transducer in order to ensure measurable amplitude of excited guided wave. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a points belonging to a defined mesh. This non-contact tool allowed to investigate phenomena related to wave propagation. For both techniques numerical signals processing tools were developed. These numerical tools were designed to extract damage relevant features from EMI measurements and guided wave propagation measurements. The damage index (DI) was introduced on the basis of the extracted features.

Guided Waves for Aircraft Panel Monitoring

2013 ◽  
Vol 558 ◽  
pp. 107-115 ◽  
Author(s):  
Pawel Malinowski ◽  
Tomasz Wandowski ◽  
Wieslaw Ostachowicz
Keyword(s):  
Signal Processing ◽  
Wave Propagation ◽  
Laser Scanning ◽  
Guided Waves ◽  
Guided Wave ◽  
Contactless Measurement ◽  
Measurement Technology ◽  
Additional Mass ◽  
Guided Wave Propagation ◽  
Panel Surface

The reported research concerns experimental investigation toward the monitoring of an aircraft panel. Guided wave propagation phenomena were used to obtain information about the state of the monitored structure. A curved aluminium panel with rivets was investigated. Piezoelectric transducer was used to excite guided waves in chosen structural element. The generated signal was amplified before applying it to the transducer in order to ensure measurable amplitude of excited guided waves. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a points belonging to a defined mesh. This contactless measurement technique allowed to investigate phenomena related to wave propagation in the aircraft panel. In the first stage, due to high complexity of the element, baseline measurements were taken. Next, a discontinuity (additional mass) was introduced on the panel surface and the measurements were repeated. Signal processing methods for features extraction from signals were proposed. These features were applied in order to detect and localize the presence anomalies in the investigated panel. The signal processing was conducted in MATLAB with the procedures developed by the authors. The used measurement technology (vibrometer) allowed to register whole wavefield of the propagating guided waves. This allowed to visualize the interaction of the waves with rivets. After introducing the discontinuity on the panel surface wave interaction with it was investigated. Two positions of the additional mass were considered. One just before the riveted stiffener and second after the stiffener. Because of this the influence of the stiffener on the damage detection abilities could be investigated. It can be concluded that the guided wave can be used for monitoring of such complex structures. The vibrometer measurements allowed learn about the guided wave propagation phenomena and perform successful damage localization.

scholarly journals Temperature affected guided wave propagation in a composite plate complementing the Open Guided Waves Platform

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Jochen Moll ◽  
Christian Kexel ◽  
Serena Pötzsch ◽  
Marcel Rennoch ◽  
Axel S. Herrmann
Keyword(s):  
Wave Propagation ◽  
Temperature Effect ◽  
Guided Waves ◽  
Measurement Data ◽  
Guided Wave ◽  
Assessment Development ◽  
Cfrp Plate ◽  
Guided Wave Propagation ◽  
Wide Range ◽  
Technical Validation

Abstract The influence of temperature is regarded as particularly important for a structural health monitoring system based on ultrasonic guided waves. Since the temperature effect causes stronger signal changes than a typical defect, the former must be addressed and compensated for reliable damage assessment. Development of new temperature compensation techniques as well as the comparison of existing algorithms require high-quality benchmark measurements. This paper investigates a carbon fiber reinforced plastic (CFRP) plate that was fully characterized in previous research in terms of stiffness tensor and guided wave propagation. The same CFRP plate is used here for the analysis of the temperature effect for a wide range of ultrasound frequencies and temperatures. The measurement data are a contribution to the Open Guided Waves (OGW) platform: http://www.open-guided-waves.de. The technical validation includes initial results on the analysis of phase velocity variations with temperature and exemplary damage detection results using state-of-the-art signal processing methods that aim to suppress the temperature effect.

scholarly journals Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5443 ◽  
Author(s):  
Anurag Dhutti ◽  
Saiful Asmin Tumin ◽  
Wamadeva Balachandran ◽  
Jamil Kanfoud ◽  
Tat-Hean Gan
Keyword(s):  
High Temperature ◽  
Guided Waves ◽  
Elevated Temperatures ◽  
Element Model ◽  
Wave Mode ◽  
Guided Wave ◽  
Electromechanical Impedance ◽  
Active Sensor ◽  
Ultrasonic Guided Wave ◽  
Modes Of Vibration

High-temperature (HT) ultrasonic transducers are of increasing interest for structural health monitoring (SHM) of structures operating in harsh environments. This article focuses on the development of an HT piezoelectric wafer active sensor (HT-PWAS) for SHM of HT pipelines using ultrasonic guided waves. The PWAS was fabricated using Y-cut gallium phosphate (GaPO4) to produce a torsional guided wave mode on pipes operating at temperatures up to 600 °C. A number of confidence-building tests on the PWAS were carried out. HT electromechanical impedance (EMI) spectroscopy was performed to characterise piezoelectric properties at elevated temperatures and over long periods of time (>1000 h). Laser Doppler vibrometry (LDV) was used to verify the modes of vibration. A finite element model of GaPO4 PWAS was developed to model the electromechanical behaviour of the PWAS and the effect of increasing temperatures, and it was validated using EMI and LDV experimental data. This study demonstrates the application of GaPO4 for guided-wave SHM of pipelines and presents a model that can be used to evaluate different transducer designs for HT applications.

scholarly journals Analysis of Guided Wave Propagation in a Multi-Layered Structure in View of Structural Health Monitoring

2019 ◽  
Vol 9 (21) ◽  
pp. 4600 ◽  
Author(s):  
Yevgeniya Lugovtsova ◽  
Jannis Bulling ◽  
Christian Boller ◽  
Jens Prager
Keyword(s):  
Wave Propagation ◽  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Guided Waves ◽  
Oil And Gas ◽  
Numerical Approach ◽  
Guided Wave ◽  
Mode Shapes ◽  
Engineering Structures ◽  
Structural Health

Guided waves (GW) are of great interest for non-destructive testing (NDT) and structural health monitoring (SHM) of engineering structures such as for oil and gas pipelines, rails, aircraft components, adhesive bonds and possibly much more. Development of a technique based on GWs requires careful understanding obtained through modelling and analysis of wave propagation and mode-damage interaction due to the dispersion and multimodal character of GWs. The Scaled Boundary Finite Element Method (SBFEM) is a suitable numerical approach for this purpose allowing calculation of dispersion curves, mode shapes and GW propagation analysis. In this article, the SBFEM is used to analyse wave propagation in a plate consisting of an isotropic aluminium layer bonded as a hybrid to an anisotropic carbon fibre reinforced plastics layer. This hybrid composite corresponds to one of those considered in a Type III composite pressure vessel used for storing gases, e.g., hydrogen in automotive and aerospace applications. The results show that most of the wave energy can be concentrated in a certain layer depending on the mode used, and by that damage present in this layer can be detected. The results obtained help to understand the wave propagation in multi-layered structures and are important for further development of NDT and SHM for engineering structures consisting of multiple layers.

Ultrasonic Guided Wave Testing of Finned Tubing

2015 ◽  
Author(s):  
Owen M. Malinowski ◽  
Matthew S. Lindsey ◽  
Jason K. Van Velsor
Keyword(s):  
Wave Propagation ◽  
Guided Waves ◽  
Tube Wall ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Complex Nature ◽  
Inspection Method ◽  
Ultrasonic Guided Wave ◽  
Guided Wave Propagation ◽  
Wave Modes

In the past few decades, ultrasonic guided waves have been utilized more frequently Non-Destructive Testing (NDT); most notably, in the qualitative screening of buried piping. However, only a fraction of their potential applications in NDT have been fully realized. This is due, in part, to their complex nature, as well as the high level of expertise required to understand and utilize their propagation characteristics. The mode/frequency combinations that can be generated in a particular structure depend on geometry and material properties and are represented by the so-called dispersion curves. Although extensive research has been done in ultrasonic guided wave propagation in various geometries and materials, the treatment of ultrasonic guided wave propagation in periodic structures has received little attention. In this paper, academic aspects of ultrasonic guided wave propagation in structures with periodicity in the wave vector direction are investigated, with the practical purpose of developing an ultrasonic guided wave based inspection technique for finned tubing. Theoretical, numerical, and experimental methods are employed. The results of this investigation show excellent agreement between theory, numerical modeling, and experimentation; all of which indicate that ultrasonic guided waves will propagate coherently in finned tube only if the proper wave modes and frequencies are selected. It is shown that the frequencies at which propagating wave modes exist can be predicted theoretically and numerically, and depend strongly on the fin geometry. Furthermore, the results show that these propagating wave modes are capable of screening for and identifying the axial location of damage in the tube wall, as well as separation of the fins from the tube wall. The conclusion drawn from these results is that Guided Wave Testing (GWT) is a viable inspection method for screening finned tubing.

Analysis of Corrosion Areas in Pipelines Using Guided Wave Propagation: Numerical Simulations and Experimental Tests

2013 ◽  
Author(s):  
Florin Turcu ◽  
Francesco Bertoncini ◽  
Giuseppe Giunta ◽  
Marco Raugi
Keyword(s):  
Wave Propagation ◽  
Numerical Methods ◽  
Numerical Simulations ◽  
Guided Waves ◽  
Experimental Tests ◽  
Field Testing ◽  
Guided Wave ◽  
Coherent Noise ◽  
Guided Wave Propagation ◽  
Integrity Issue

Guided Waves (GW) have become widely used for the inspection of unpiggable and inaccessible pipelines because of the presence of coating, because of their position or because they are buried. Among the possible anomalies, corrosion is the main integrity issue affecting pipelines. The effect that corrosion has on guided wave propagation is attenuation and increased coherent noise when it is generalized or reflection when corrosion is localized. In this paper, the possibility to characterize corrosion areas affecting pipelines through long range guided wave inspection or monitoring is investigated. With this purpose field testing was performed and the results were used for the validation of numerical methods able to simulate the phenomenon.

Guided Wave Propagation and Interaction with Damage in Tubular Structures

2008 ◽  
Vol 32 ◽  
pp. 289-292
Author(s):  
Ye Lu ◽  
Lin Ye ◽  
Dong Wang ◽  
Guang Meng
Keyword(s):  
Wave Propagation ◽  
Wave Scattering ◽  
Guided Waves ◽  
Guided Wave ◽  
Tube Surface ◽  
Tubular Structures ◽  
Active Sensor ◽  
Guided Wave Propagation ◽  
Rectangular Tube ◽  
Signal Correlation

A piezoelectric active sensor network is configured to collect the wave scattering from a throughthickness hole on an aluminium rectangular tube. It is found that guided waves are capable of propagating across the tube edges, while keeping the sensitivity to the damage even not on surfaces where the actuator and sensor are located. Signal correlation between the intact and damaged structure is evaluated and the probability distribution of damage is thus achieved on the unfolded tube surface.

scholarly journals Slow waves in fractures filled with viscous fluid

Geophysics ◽  
2008 ◽  
Vol 73 (1) ◽  
pp. N1-N7 ◽  
Author(s):  
Valeri Korneev
Keyword(s):  
Wave Propagation ◽  
Viscous Fluid ◽  
Guided Waves ◽  
Seismic Wave Propagation ◽  
Guided Wave ◽  
Resonance Excitation ◽  
Wave Propagation Velocity ◽  
Low Frequencies ◽  
Infinite Layer

Stoneley guided waves in a fluid-filled fracture generally have larger amplitudes than other waves; therefore, their properties need to be incorporated into more realistic models. A fracture is modeled as an infinite layer of viscous fluid bounded by two elastic half-spaces with identical parameters. For small fracture thickness, a simple dispersion equation for wave-propagation velocity is obtained. This velocity is much smaller than the velocity of a fluid wave in a Biot-type solution, in which fracture walls are assumed to be rigid. At seismic prospecting frequencies and realistic fracture thicknesses, the Stoneley guided wave has wavelengths on the order of several meters and a quality factor [Formula: see text] exceeding 10, which indicates the possibility of resonance excitation in fluid-bearing rocks. The velocity and attenuation of Stoneley guided waves are distinctly different at low frequencies for water and for oil. The predominant role of fractures in fluid flow at field scales is supported by permeability data, showing an increase of several orders of magnitude when compared with values obtained at laboratory scales. The data suggest that Stoneley guided waves should be taken into account in theories describing seismic wave propagation in fluid-saturated rocks.

Evaluation of Adhesive Interface Properties in Honeycomb Sandwich Structure Using Guided Waves

2021 ◽  
Author(s):  
Parambeer Singh Negi ◽  
Dileep Koodalil ◽  
Krishnan Balasubramaniam
Keyword(s):  
Wave Propagation ◽  
Sandwich Structure ◽  
Guided Waves ◽  
Wave Mode ◽  
Guided Wave ◽  
Sh Wave ◽  
Bond Quality ◽  
Honeycomb Sandwich ◽  
Oriented Parallel ◽  
Honeycomb Sandwich Structure

Abstract A method is presented to evaluate the interfacial weakness of aluminium-based honeycomb sandwich structure (HSS) using Shear Horizontal (SH) guided wave. SH guided waves are sensitive to the interfacial properties since the wave particles vibration is oriented parallel to the adhesive-adherent joints. Periodic permanent magnet (PPM) electromagnetic acoustic transducers (EMATs) are used to excite and detect SH-guided waves. A semi-analytical finite element method is developed to simulate the SH wave propagation in HSS. The boundary stiffness approach is used to model the adhesive-adherent interface. The excitation parameters are chosen such that only SH0 mode is generated in the structure. The interaction of the fundamental SH0 wave mode with various defects and the different interface stiffness is analyzed. The frequency-wavenumber analysis is used to study the effect of interface stiffness on SH wave propagation. The analysis reveals that in a perfect bond, SH0 and S0 guided modes are present. The interaction of SH0 mode with the honeycomb core results in the genesis of S0 mode. Thus, the presence or absence of the S0 mode can be used as an indicator of bond quality. The findings from the FE simulation are validated against the experiment. The analysis shows a reliable non-destructive evaluation of the interface joint and classifying them as good or bad bonds.

Acoustic Wave Propagation Simulation in Double-Layered Composite Cylindrical Structures

2013 ◽  
Author(s):  
Jikai Du
Keyword(s):  
Wave Propagation ◽  
Carbon Fiber ◽  
Fiber Orientation ◽  
Guided Waves ◽  
Layered Composite ◽  
Guided Wave ◽  
Ultrasound Wave ◽  
Ultrasound Guided ◽  
Cylindrical Structures ◽  
Guided Wave Propagation

Ultrasound guided waves have been recognized as an effective tool for the rapid and long-range inspection of composite cylindrical structures, but its application is still limited due to the complex nature of guided waves and their interactions with material geometry and material properties. This paper uses finite element technique to simulate the ultrasound guided wave propagation in layered composite cylinders. Ultrasound guided wave propagation was analyzed in a double-layered cylinder composed of an anisotropic unidirectional carbon fiber/epoxy resin composite layer wrapped on an isotropic aluminum cylinder. The carbon fiber orientation is either along the cylinder circumferential direction or axial direction. Ultrasound wave is excited from a PZT-4 transducer which is placed on the top of a Plexiglas wedge to adjust the ultrasound incident angle into the cylinder. Low ultrasound frequencies at 0.5 and 1.0 MHz were selected to improve the effect of attenuation and simulation efficiency. Wave propagation velocities and wave structures were analyzed at various positions of the cylinder. This study helped to examine the effect of fiber orientation on wave dispersion characteristics and to assess the feasibility of applying ultrasound guided wave technique for the evaluation of composite cylindrical structures.

Sign in / Sign up

Export Citation Format

Share Document