Damage study of structures using Hotteling's t2 curve in electromechanical impedance method

2021 ◽  
Author(s):  
Shishir Kumar Singh ◽  
Pawel Malinowski
Keyword(s):  
Impedance Method ◽  
Electromechanical Impedance ◽  
Damage Study

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.

Non Destructive Evaluation Based on Impedance Method Using Embedded PZT Sensor

2009 ◽  
Vol 79-82 ◽  
pp. 35-38 ◽  
Author(s):  
Dong Yu Xu ◽  
Xin Cheng ◽  
Shi Feng Huang ◽  
Min Hua Jiang
Keyword(s):  
Structural Damage ◽  
Crack Depth ◽  
Impedance Method ◽  
Impedance Spectra ◽  
Electromechanical Impedance ◽  
Non Destructive Evaluation ◽  
Increasing Trend ◽  
Impedance Technique ◽  
Impedance Curve ◽  
Non Destructive

The structural damage of mortar caused by simulated crack was evaluated using embedded PZT sensor combining with dynamic electromechanical impedance technique. The influence of embedded PZT sensors layout on detecting structural damage induced by the simulated cracks was also investigated. The results indicate that with increasing the simulated crack depth, the impedance real part of PZT sensors shift leftwards accompanying with the appearance of new peaks in the spectra. When more simulated cracks occur, the shift of the impedance curve becomes more obvious, and the amounts of new peaks in the impedance spectra also increase. RMSD indices of the structures with PZT sensors embedded in them with different layout can show the structural incipient damage clearly. With increasing more simulated cracks in the mortar structures, RMSD values of the structures with different PZT sensors layout become larger, under the same depth, RMSD indices of the structures with PZT sensor embedded transversely and horizontally in them show the increasing trend.

scholarly journals A PZT-Based Electromechanical Impedance Method for Monitoring the Soil Freeze–Thaw Process

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1107 ◽  
Author(s):  
Jicheng Zhang ◽  
Chuan Zhang ◽  
Jiahao Xiao ◽  
Jinwei Jiang
Keyword(s):  
Stress Wave ◽  
Lead Zirconate Titanate ◽  
Soil Freezing ◽  
Impedance Method ◽  
Active Sensing ◽  
Freezing And Thawing ◽  
Engineering Structures ◽  
Electromechanical Impedance ◽  
Freeze Thaw ◽  
Wave Signal

It is important to conduct research on the soil freeze–thaw process because concurrent adverse effects always occur during this process and can cause serious damage to engineering structures. In this paper, the variation of the impedance signature and the stress wave signal at different temperatures was monitored by using Lead Zirconate Titanate (PZT) transducers through the electromechanical impedance (EMI) method and the active sensing method. Three piezoceramic-based smart aggregates were used in this research. Among them, two smart aggregates were used for the active sensing method, through which one works as an actuator to emit the stress wave signal and the other one works as a sensor to receive the signal. In addition, another smart aggregate was employed for the EMI testing, in which it serves as both an actuator and a receiver to monitor the impedance signature. The trend of the impedance signature with variation of the temperature during the soil freeze–thaw process was obtained. Moreover, the relationship between the energy index of the stress wave signal and the soil temperature was established based on wavelet packet energy analysis. The results demonstrate that the piezoceramic-based electromechanical impedance method is reliable for monitoring the soil freezing and thawing process.

Nonlinear Modeling of Cracked Beams for Impedance Based Structural Health Monitoring

2017 ◽  
Author(s):  
Naserodin Sepehry ◽  
Firooz Bakhtiari-Nejad ◽  
Mahnaz Shamshirsaz ◽  
Weidong Zhu
Keyword(s):  
Structural Health Monitoring ◽  
Linear System ◽  
Frequency Response ◽  
Frequency Domain ◽  
Health Monitoring ◽  
Impedance Method ◽  
Breathing Crack ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
System Equations

One of the main objectives of the structural health monitoring by piezoelectric wafer active sensor (PWAS) using electromechanical impedance method is continuously damage detection applications. In present work impedance method of beam structure is considered and the effect of early crack using breathing crack modeling is studied. In order to model the effect of a crack in beam, the beam is connected with a rotational spring in crack location. The Rayleigh–Ritz method is used to generate ordinary differential equation of cracked beam. Firstly, only open crack is considered that this is leads to linear system equation. In linear system, time domain system equations are converted to frequency domain, and then impedance of PWAS in frequency domain is calculated. Secondly, the breathing crack is modeled to be fully open or fully closed. This phenomenon leads to the nonlinear system equations. These nonlinear equations are solved using pseudo-arc length continuation scheme and collocation method for any harmonic voltage applied to actuator. Then impedance of PWAS is calculated. Two methods are used to detect early crack using breathing crack modeling on PWAS impedance. At the first, frequency response of breathing crack in the frequency range with its sub-harmonics is calculated. Second, only frequency response of one harmonic is computed with its super-harmonics. Finally, the detection method of linear is compared with nonlinear model.

Polynomial Chaos Expansion Sensitivity Analysis for Electromechanical Impedance of Plate

2016 ◽  
Author(s):  
Firooz Bakhtiari-Nejad ◽  
Naserodin Sepehry ◽  
Mahnaz Shamshirsaz
Keyword(s):  
Sensitivity Analysis ◽  
Polynomial Chaos ◽  
Probabilistic Method ◽  
Polynomial Chaos Expansion ◽  
Impedance Method ◽  
Chaos Expansion ◽  
Electromechanical Impedance ◽  
Plate Structure ◽  
Spectral Finite Element ◽  
Uncertainty Parameters

Piezoelectric wafer active sensors (PWAS) have been the widely used in impedance based damage detection applications. A most important matter in impedance method is applied voltage to PWAS and measuring current in PWAS. In this paper, for modeling of impedance based structural health monitoring, a 3D spectral finite element method (SFEM) is developed for plate structure with PWAS. Because of high frequency application of impedance method, high degree of freedom (DOF) is needed for modeling of impedance of PWAS attached on the plate. Uncertainty of plate and PWAS parameters could be effect on the natural frequencies of structure. So, impedance signal of modeling would be different based on uncertainty parameters. Polynomial chaos expansion (PC) is a probabilistic method consisting in the projection of the model output on a basis of orthogonal stochastic polynomials in the random inputs. In this paper, PCE is used for sensitivity analysis of the electromechanical impedance of plate structure with PWAS.

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