Dynamic analysis of a piezoelectric augmented beam system with adhesive bonding layer effects

2016 ◽  
Vol 28 (2) ◽  
pp. 178-194 ◽  
Author(s):  
Mohammad I. Albakri ◽  
Pablo A. Tarazaga
Keyword(s):  
Dynamic Response ◽  
High Frequency ◽  
Adhesive Bonding ◽  
Spectral Element ◽  
Bonding Layer ◽  
Inertia Effects ◽  
Electromechanical Impedance ◽  
Beam System ◽  
Host Structure ◽  
Piezoelectric Wafers

Embedded and surface bonded piezoelectric wafers have been widely used for control and monitoring purposes. Several nondestructive evaluation and structural health monitoring techniques, such as electromechanical impedance and wave propagation–based techniques, utilize piezoelectric wafers in either active or passive manner to interrogate the host structure. The basis of all these techniques is the energy transfer between the piezoelectric wafer and the host structure which takes place through an adhesive bonding layer. In this article, the high-frequency dynamic response of a coupled piezoelectric-beam system is modeled including the adhesive bonding layer in between. A new three-layer spectral element is developed for this purpose. The formulation of this new element takes into account axial and shear deformations, in addition to rotary inertia effects in all three layers. The capabilities of the proposed model are demonstrated through several numerical examples, where the effects of bonding layer geometric and material characteristics on dispersion relations and damage detection capabilities are discussed. The results highlight the importance of accounting for the adhesive bonding layer in piezoelectric-structure interaction models, especially when the high-frequency dynamic response is of interest.

Time-domain spectral element method for modelling of the electromechanical impedance of disbonded composites

2018 ◽  
Vol 29 (16) ◽  
pp. 3214-3221 ◽  
Author(s):  
Piotr Fiborek ◽  
Paweł H Malinowski ◽  
Paweł Kudela ◽  
Tomasz Wandowski ◽  
Wiesław M Ostachowicz
Keyword(s):  
Spectral Element Method ◽  
Spectral Element ◽  
Impedance Method ◽  
Adhesively Bonded ◽  
Destructive Testing ◽  
Electromechanical Impedance ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Non Destructive ◽  
Element Method

The research focuses on the electromechanical impedance method. The electromechanical impedance method can be treated as non-destructive testing or structural health monitoring approach. It is important to have a reliable tool that allows verifying the integrity of the investigated objects. The electromechanical impedance method was applied here to assess the carbon fibre–reinforced polymer samples. The single and adhesively bonded samples were investigated. In the reported research, the electromechanical impedance spectra up to 5 MHz were considered. The investigation comprised of modelling using spectral element method and experimental measurements. Numerical and experimental spectra were analysed. Differences in spectra caused by differences in considered samples were observed.

High-frequency seismic wave modelling of the deep Earth based on hybrid methods and spectral-element simulations: a conceptual study

2019 ◽  
Vol 219 (3) ◽  
pp. 1948-1969 ◽  
Author(s):  
Chuangxin Lin ◽  
Vadim Monteiller ◽  
Kai Wang ◽  
Tianshi Liu ◽  
Ping Tong ◽  
...  
Keyword(s):  
Hybrid Method ◽  
High Frequency ◽  
Hybrid Methods ◽  
Spectral Element ◽  
Small Scale ◽  
Target Region ◽  
Deep Earth ◽  
Virtual Boundary ◽  
Scale Structures ◽  
Small Scale Structures

SUMMARY Over the past few decades, seismic studies have revealed complex structural anomalies in the Earth’s deep interior at various scales, such as large low-shear-velocity provinces (LLSVPs) and ultra-low velocity zones (ULVZs) in the lowermost mantle, and small-scale scatterers in the mid-mantle. These structures which are critical for better understanding of the geodynamics and evolution of the deep Earth, need to be further resolved by high-resolution imaging techniques. The spectral-element method (SEM) can be used to accurately simulate seismic wave propagation in heterogeneous Earth models, and its application in full-waveform inversion (FWI) provides a promising high-resolution and high-fidelity imaging technique. But it can be computationally prohibitive when used to model small scale structures in the deep Earth based upon high-frequency seismic waves. The heavy computational cost can be circumvented by using hybrid methods, which restrict the main computation by SEM solver to only a small target region (e.g. above the CMB) encompassing possible 2-D/3-D anomalies, and apply efficient analytical or numerical methods to calculate the wavefield for 1-D background models. These forward modelling tools based on hybrid methods can be then used in the so-called ‘box tomography’ approach to resolve fine-structures in the deep Earth. In this study, we outline the theory of a hybrid method used to model small scale structures in the deep Earth and present its implementation based on SEM solvers in a three-step workflow. First, the wavefield generated by the source is computed for the 1-D background model with traction and velocity saved for the virtual boundary of the target region, which are then used as boundary inputs to simulate the wavefield in the target region based on absorbing boundary condition in SEM. In the final step, the total wavefield at receivers is reconstructed based upon the total wavefield on the virtual boundary computed in the previous step. As a proof-of-concept study, we demonstrate the workflow of the hybrid method based on a 2-D SEM solver. Examples of the hybrid method applied to a coupled fluid–solid model show that our workflow can accurately recover the scattered waves back to the surface. Furthermore, we benchmark the hybrid method on a realistic heterogeneous Earth model built from AK135-F and show how teleseismic scattered waves can be used to model deep Earth structures. By documenting the theory and SEM implementation of the hybrid method, our study lays the foundation for future two-way coupling of 3-D SEM solver with other efficient analytic or numerical 1-D solvers.

Impact Response Analysis of a Coaxial Double-Pipe Structure by Using Spectral Element Method

2011 ◽  
Author(s):  
Akemi Nishida ◽  
Kazuhiko Iigaki
Keyword(s):  
High Frequency ◽  
Spectral Element Method ◽  
Spectral Element ◽  
Impact Response ◽  
Response Analysis ◽  
Damping Properties ◽  
High Frequency Region ◽  
Parametric Studies ◽  
Double Pipe ◽  
Element Method

A coaxial double-pipe structure is to be used in the primary and auxiliary coolant system of a high-temperature gas-cooled reactor. In order to study the vibration characteristics of the coaxial double-pipe structure, hammering experiments were performed using specimens of the structure. Because the structural responses obtained in the experiments contained high-frequency components, impact response analysis was performed by using the spectral element method, which has high accuracy in the high-frequency region. A comparison between analysis results and experiment results showed good agreement between them. We also performed parametric studies on the damping properties of the specimens. The damping properties determined from the experiment results indicated that the inner and outer pipes had different damping properties.

scholarly journals Two-Phase Resonant Converter to Drive High-Power LED Lamps

Electronics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 53 ◽  
Author(s):  
Christian Brañas ◽  
Rosario Casanueva ◽  
Francisco J. Díaz ◽  
Francisco J. Azcondo
Keyword(s):  
Dynamic Response ◽  
High Power ◽  
High Frequency ◽  
Pulsed Current ◽  
Resonant Converter ◽  
Two Phase ◽  
Street Lighting ◽  
Spice Model ◽  
Flicker Effect ◽  
Output Filter

This paper presents the design and modeling of a two-phase resonant converter that drives a LED lamp with a high-frequency pulsed current free of instabilities and flicker effect, fulfilling the recommendations of the IEEE PAR 1789-2015, so that it enables visible light-based communication at a 10 kB/s bit rate. The dynamic study of the converter takes into consideration the effect of the reflected impedance of the output filter on the AC side. In order to evaluate the dynamic response of the converter, a Spice model is defined. A 120 W prototype intended for street lighting applications has been built to validate the analysis and modeling.

Application of the Fatigue Crack Opening/Closing Effect for SHM Using Electromechanical Impedance Technology

2015 ◽  
Vol 811 ◽  
pp. 228-235
Author(s):  
Vitalijs Pavelko
Keyword(s):  
Fatigue Crack ◽  
Fatigue Testing ◽  
Mechanical Load ◽  
Crack Opening ◽  
Central Fatigue ◽  
Guided Wave ◽  
Central Hole ◽  
Electromechanical Impedance ◽  
Guided Wave Propagation ◽  
Host Structure

Earlier the effect of fatigue crack opening/closing (FCOC) to ultrasound guided wave propagation was investigated. The purpose of this article is to evaluate this effect to the electromechanical impedance (EMI) of the system "piezoelectric transducer / host structure. Experimental study performed using the flat samples of aluminum alloy. One of them had the 4 mm central hole. Other sample after fatigue testing had central fatigue crack of 40 mm length (including a 4 mm central hole for the initiation of a fatigue crack. Each sample was loaded by tensile axial static load from zero to 12 kN and the EMI measurement after eacn 2 kN incrementat of load. The EMI was measured in the frequency range of 20-40 kHz. It is established that the FCOC effect to magnitude and reactance of EMI mainly associated with variation of the capacitance of PZT under mechanical load. But the effect to the PZT resistance is more complex and more significant. The result of the study is the base of some procedure of fatigue crack detecting by the EMI method without baseline use. The developed model of EMI of ’host structure – PZT’ that is based on the modal decomposition of dynamic response of this system allows to solve main problems of the SHM system designing and optimizing of its parameters.

Lateral Vibration of Offshore Piles Considering Pile-Water Interaction

2019 ◽  
Vol 19 (12) ◽  
pp. 1950147 ◽  
Author(s):  
Peng Fu ◽  
Kanghe Xie
Keyword(s):  
Dynamic Response ◽  
High Frequency ◽  
Hydrodynamic Force ◽  
Hydrodynamic Pressure ◽  
Frequency Range ◽  
Water Interaction ◽  
Dynamic Impedance ◽  
Separation Of Variable ◽  
Soil Interface ◽  
Offshore Piles

The dynamic response of an offshore pile in saturated soil subjected to lateral harmonic loading is theoretically investigated by considering the dynamic pile-water interaction. The governing equation of water is solved based on the separation of variable method, and the analytical expression of the hydrodynamic force applied on the pile is then obtained. Based on the continuous conditions at the pile-soil interface and pile-water interface, the analytical solution of the dynamic impedance of the offshore pile is derived by using transfer matrix method. To verify this solution, the dynamic impedance obtained for a cylinder in water is compared with that of a partially embedded pile. Based on this solution, the effect of hydrodynamic pressure and other parameters on the dynamic response of offshore piles is investigated. The results show that the analytical model ignoring the hydrodynamic force applied on the pile misestimates the impedance of the pile in the high frequency range.

Finite Element Model for Cracked Beams with Bonded Piezoelectric Transducers

2011 ◽  
Vol 94-96 ◽  
pp. 73-76
Author(s):  
Wei Yan ◽  
Wan Chun Li ◽  
Wei Wang
Keyword(s):  
Finite Element ◽  
Mass Density ◽  
Crack Depth ◽  
Element Model ◽  
Numerical Results ◽  
Parameter Study ◽  
Bonding Layer ◽  
Cracked Beam ◽  
Electromechanical Impedance ◽  
Finite Element Software

Based on the finite element software ANSYS, an electromechanical impedance (EMI) model for a cracked beam with imperfectly bonded piezoelectric patches is established in the paper. The property of bonding layer between the PZT sensor/actuators and the host beam is taken into account and thus the three-dimensional (3D) model of piezoelectric patch-adhesive-cracked beam coupled system is developed. Comparison with existing numerical results validates the effectiveness and accuracy of the present analysis. Then, parameter study is conducted by considering effects of the vibration mode of the host beam, the mass density of the adhesive and crack depth etc. on EMI signatures. The numerical results indicate that the present EMI model can be used to detect the cracks in the structures.

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