Damage Size Estimation for Composite Laminates Based on an Anisotropic Wavefront Expression

2020 ◽  
Author(s):  
M. Saqib Hameed ◽  
Zheng Li ◽  
Kaihong Zheng
Keyword(s):  
Lead Zirconate Titanate ◽  
Composite Laminates ◽  
Least Squares Method ◽  
Lamb Waves ◽  
Lead Zirconate ◽  
Gabor Wavelet ◽  
Size Estimation ◽  
Edge Points ◽  
Square Cells ◽  
Size Evaluation

Abstract A Multistage Elliptical Parametric (MEP) method is developed in this research for damage size evaluation in anisotropic composite laminates. The Lamb waves are actuated and sensed using piezoelectric (lead zirconate titanate, PZT) transducers arranged as a network of square cells. The dynamic response signals are processed using a continuous wavelet transformation (CWT) based on the Gabor wavelet for accurate time of flight (ToF) measurements. A numerical method is developed for the construction of non-elliptic path loci for each actuator-sensor pair. The damage is localized first using the least squares method, and then the damage edge points are located on each non-elliptic path loci as points which have the minimum distance from the damage location. The MEP method based on the damage edge points is implemented in multiple stages for damage size evaluation in a cross-ply laminate. Each stage is designed on the basis on excitation of specific prearranged transducers inside the square cell. The results indicate that the MEP method can quantitatively estimate the size of an elliptical damage in cross-ply laminates.

scholarly journals Lamb-Wave-Based Multistage Damage Detection Method Using an Active PZT Sensor Network for Large Structures

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2010 ◽  
Author(s):  
Hameed ◽  
Li ◽  
Chen ◽  
Qi
Keyword(s):  
Damage Detection ◽  
Lead Zirconate Titanate ◽  
Lamb Wave ◽  
Detection Method ◽  
Lead Zirconate ◽  
Processing Technique ◽  
Vital Role ◽  
Gabor Wavelet ◽  
Size Estimation ◽  
Detection Cell

A multistage damage detection method is introduced in this work that uses piezoelectric lead zirconate titanate (PZT) transducers to excite/sense the Lamb wave signals. A continuous wavelet transformation (CWT), based on the Gabor wavelet, is applied to accurately process the complicated wave signals caused by the damage. For a network of transducers, the damage can be detected in one detection cell based on the signals scattered by the damage, and then it can be quantitatively estimated by three detection stages using the outer tangent circle and least-squares methods. First, a single-stage damage detection method is carried out by exciting a transducer at the center of the detection cell to locate the damaged subcell. Then, the corner transducers are excited in the second and third stages of detection to improve the damage detection, especially the size estimation. The method does not require any baseline signal, and it only utilizes the same arrangement of transducers and the same data processing technique in all stages. The results from previous detection stages contribute to the improvement of damage detection in the subsequent stages. Both numerical simulation and experimental evaluation were used to verify that the method can accurately quantify the damage location and size. It was also found that the size of the detection cell plays a vital role in the accuracy of the results in this Lamb-wave-based multistage damage detection method.

The Use of Correlation and Frequency Analysis for Detection of Deformation in 7050 Aluminum Beams

2015 ◽  
Vol 655 ◽  
pp. 263-266
Author(s):  
Fei Yi Liao ◽  
Shi Jun Li ◽  
Yuan Lin
Keyword(s):  
Frequency Domain ◽  
Lead Zirconate Titanate ◽  
Lamb Waves ◽  
Piezoelectric Materials ◽  
Lead Zirconate ◽  
Bending Test ◽  
Test Machine ◽  
Three Point Bending ◽  
Potential Applications ◽  
Aluminum Beam

Lead zirconate titanate (PZT) is one of the most widely used ferroelectric and piezoelectric materials. Its piezoelectricity is widely used in the applications of structural health monitoring (SHM). Here, we use PZT ceramics as sensors to detect the deformation of structure using guided Lamb waves. In order to well analyze the multi-modes of Lamb waves and achieve detection of deformation in superposed wave peaks, correlation and Fourier transform were used to extract peaks in both time and frequency domain. In this paper, a 7050 aluminum beam and three-point bending test machine were utilized to test the changes of waves when different deformations were introduced. With the adjustment of correlation index, change of time delay and new peaks occurring in time domain demonstrated the change of deformations. In frequency domain, the change of central frequencies and magnitudes also demonstrated the change of deformations. The study shows the potential applications of PZT sensors in detection of deformation.

Damage Index Comparison for a Composite Stiffened Panel Using Lamb Wave

2007 ◽  
Vol 26-28 ◽  
pp. 1265-1268 ◽  
Author(s):  
Chan Yik Park
Keyword(s):  
Lead Zirconate Titanate ◽  
Lamb Waves ◽  
Impact Damage ◽  
Damage Index ◽  
Lead Zirconate ◽  
Low Velocity Impact ◽  
Stiffened Panel ◽  
Low Velocity ◽  
Composite Stiffened Panel ◽  
Index Comparison

Various damage index (DI) algorithms of detecting changes such as a loosen bolt and a delamination development in a composite structure were examined using ultrasonic Lamb waves generated by embedded piezoelectric active sensors. The DI is a single value that is a function of response signal’s attenuation due to any damage or changes in a structure. Various DI algorithms such as active damage interrogation (ADI), time domain root men square (RMS), short time Fourier Transform (STFT) and time reversal (TR) were discussed. For experimental validation, a composite stiffened panel was used, and loosen bolt damage and low-velocity- impact damage were tested. In order to pitch and catch Lamb waves, surface mounted PZTs (lead zirconate titanate) were used. According to the DI algorithms, appropriate ultrasonic guided Lamb waves were selected for actuators. Each set of DI algorithm and drive signal showed different characteristics to detect the damage.

Convergent-bceam diffraction studies on lead zirconate titanate Ceramics

1986 ◽  
Vol 44 ◽  
pp. 482-483
Author(s):  
M.L.A. Dass ◽  
T.A. Bielicki ◽  
G. Thomas ◽  
T. Yamamoto ◽  
K. Okazaki
Keyword(s):  
Lead Zirconate Titanate ◽  
Direct Proof ◽  
Lead Zirconate ◽  
Subsolidus Phase ◽  
Pzt Ceramics ◽  
Subsolidus Phase Diagram ◽  
Zirconate Titanate ◽  
Two Phases ◽  
Cbd Method ◽  
Titanate Ceramics

Lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), ceramics are ferroelectrics formed as solid solutions between ferroelectric PbTiO3 and ant iferroelectric PbZrO3. The subsolidus phase diagram is shown in figure 1. PZT transforms between the Ti-rich tetragonal (T) and the Zr-rich rhombohedral (R) phases at a composition which is nearly independent of temperature. This phenomenon is called morphotropism, and the boundary between the two phases is known as the morphotropic phase boundary (MPB). The excellent piezoelectric and dielectric properties occurring at this composition are believed to.be due to the coexistence of T and R phases, which results in easy poling (i.e. orientation of individual grain polarizations in the direction of an applied electric field). However, there is little direct proof of the coexistence of the two phases at the MPB, possibly because of the difficulty of distinguishing between them. In this investigation a CBD method was found which would successfully differentiate between the phases, and this was applied to confirm the coexistence of the two phases.

Ion Beam Sputter Deposition Of Ferroelectric Oxide Thin Films

1991 ◽  
Vol 223 ◽  
Author(s):  
Thomas M. Graettinger ◽  
O. Auciello ◽  
M. S. Ameen ◽  
H. N. Al-Shareef ◽  
K. Gifford ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Growth Parameters ◽  
Ion Beam ◽  
Lead Zirconate ◽  
Electro Optic ◽  
Integrated Optical ◽  
Pzt Films ◽  
Ion Beam Sputter Deposition ◽  
Ferroelectric Oxide

ABSTRACTFerroelectric oxide films have been studied for their potential application as integrated optical materials and nonvolatile memories. Electro-optic properties of potassium niobate (KNbO3) thin films have been measured and the results correlated to the microstructures observed. The growth parameters necessary to obtain single phase perovskite lead zirconate titanate (PZT) thin films are discussed. Hysteresis and fatigue measurements of the PZT films were performed to determine their characteristics for potential memory devices.

Mathematical model to predict the characteristics of polarization in dielectric materials: The concept of piezoelectrcity and electrostriction

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mathematical Model ◽  
Electric Field ◽  
Lead Zirconate Titanate ◽  
Dielectric Material ◽  
Strain Curve ◽  
Dielectric Materials ◽  
Lead Zirconate ◽  
Simulation Software ◽  
Constitutive Law ◽  
Basic Material

Model was developed for the prediction of polarization characteristics in a dielectric material exhibiting piezoelectricity and electrostriction based on mathematical equations and MATLAB computer simulation software. The model was developed based on equations of polarization and piezoelectric constitutive law and the functional coefficient of Lead Zirconate Titanate (PZT) crystal material used was 2.3×10-6 m (thickness), the model further allows the input of basic material and calculation of parameters of applied voltage levels, applied stress, pressure, dielectric material properties and so on, to generate the polarization curve, strain curve and the expected deformation change in the material length charts. The mathematical model revealed that an application of 5 volts across the terminals of a 2.3×10-6 m thick dielectric material (PZT) predicted a 1.95×10-9 m change in length of the material, which indicates piezoelectric properties. Both polarization and electric field curve as well as strain and voltage curve were also generated and the result revealed a linear proportionality of the compared parameters, indicating a resultant increase in the electric field yields higher polarization of the dielectric materials atmosphere.

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