scholarly journals An Omnidirectional Near-Field Comprehensive Damage Detection Method for Composite Structures

2019 ◽  
Vol 9 (3) ◽  
pp. 567 ◽  
Author(s):  
Zhiling Wang ◽  
Zhenwei Xiao ◽  
Yonglin Li ◽  
Yudong Jiang
Keyword(s):  
Composite Materials ◽  
Damage Detection ◽  
Phased Array ◽  
Detection Method ◽  
Near Field ◽  
Imaging Method ◽  
Field Sampling ◽  
Damage Monitoring ◽  
Damage Imaging ◽  
Ultrasonic Phased Array

As one of the active structural health monitoring methods based on the Lamb wave, the ultrasonic phased-array damage detection method can provide information such as damage location and range more intuitively, which is why this method is a research hotspot in the field of Lamb wave-based damage monitoring. However, the ultrasonic phased-array damage detection method intended for the far field is not applicable to near-field damage monitoring. In addition, the traditional one-dimensional piezoelectric phased-array damage imaging method suffers from a blind area in the near field, and the data collection time of its angle scanning is relatively long. In view of these problems, this paper proposes an omnidirectional damage imaging monitoring method, combining the near-field sampling phased-array damage monitoring algorithm and the two-dimensional phased-array. The proposed method is verified by experiments using complex composite materials, and the results obtained show that the proposed omnidirectional near-field sampling phased-array damage imaging method is suitable for real-time damage detection in complex composite materials.

scholarly journals Using Phased Array Technology and Embedded Ultrasonic Structural Radar for Active Structural Health Monitoring and Nondestructive Evaluation

2005 ◽  
Author(s):  
Lingyu Yu ◽  
Victor Giurgiutiu
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Phased Array ◽  
Near Field ◽  
Experimental Tests ◽  
Successful Implementation ◽  
Array Design ◽  
Array Technology ◽  
Set Up ◽  
Complicated Geometries

The embedded ultrasonic structural radar (EUSR) was developed based on phased array technology. It can interrogate large structural areas from a single location using ultrasonic guided Lamb and Rayleigh waves generated by tuned piezoelectric wafer active sensors (PWAS) that are permanently attached to the structure. This paper brings together several aspects of the implementation and application of EUSR to structural damage detection: (a) improving the near field damage detection; (b) designing optimized phased-array patterns; (c) designing a mini phased array for compact structures with complicated geometries and multiple boundaries. Firstly, we deduced a generic formulation for phased array directional beamforming using the exact traveling waves formulation without the limiting parallel-rays assumption used by other investigators. This algorithm has been implemented in the EUSR LabVIEW program and its performance has been verified through simulation and experimental tests. Secondly, we studied the beamforming and lobe steering characteristics of a 1-D linear array design. The influence of several geometry parameters was discussed in order to achieve the optimal directionality, including the number of sensors in the phased array, the spacing between adjacent sensors, and the steering direction angles. Extensive simulation studies have shown that the well-behaved directional beamforming can be achieved with judicious array design. Proof-of-concept experiments for testing these results have also been set up and the preliminary results are confirming the effectiveness of our approach. Thirdly, we investigated the possibility of applying the EUSR phased array method to compact specimens and proposed the design of a mini phased array. Laboratory experiments have been carried out to prove the successful implementation of this concept. Finally, the paper ends up with discussions and conclusions regarding the beamforming, optimization and implementation of the PWAS phased arrays, as well as suggestions for further work.

Optimization of Element Parameters for a New OPFC Ultrasonic Phased Array Transducer

2014 ◽  
Vol 609-610 ◽  
pp. 1293-1298
Author(s):  
Zi Ping Wang ◽  
Ying Luo
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Phased Array ◽  
Low Voltage ◽  
Fiber Composite ◽  
Array Element ◽  
Structural Damage Detection ◽  
Array Transducer ◽  
Verification Methods ◽  
Ultrasonic Phased Array

An orthotropic piezoelectric fiber composite (OPFC) element and related OPFC ultrasonic phased array transducer which applied in damage detection of metal structures are investigated by theoretical analysis, numerical simulation and experimental verification methods. Based on electromechanical coupling, the influence of the material characteristics and geometry parameters on actuation performance is studied for the thickness expansion type OPFC elements. In view of lack in the mechanic-electronic parameter design of the existing single PZT element for modern ultrasonic phased array transducer, the related OPFC ultrasonic phased array transducer which used in metal structural damage detection is designed, which have the merits such as low voltage and limit the effects on grating lobe. The focusing acoustic field distribution is analyzed by finite element method together with directivity analysis in metals. The optimal array parameters such as phased array element interval, array element width and number of element are obtained by studying the total displacement changes as various parameters changes at focus point. The preparation of OPFC actuator used in metal structural damage detection is studied. The performance of interdigital OPFC element is also obtained by testing and comparing with the traditional PZT element. The experimental results displayed good agreement with the theoretical predictions.

Damage imaging for composite using Lamb wave based on minimum variance distortion-less response method

2019 ◽  
Vol 41 (15) ◽  
pp. 4179-4186
Author(s):  
Chenhui Su ◽  
Mingshun Jiang ◽  
Shanshan Lv ◽  
Lei Zhang ◽  
Faye Zhang ◽  
...  
Keyword(s):  
Composite Materials ◽  
Lamb Wave ◽  
Composite Laminates ◽  
Damage Identification ◽  
Imaging System ◽  
Impact Damage ◽  
Near Field ◽  
Maximum Error ◽  
Minimum Variance ◽  
Damage Imaging

It is highly probable for the structures of carbon fiber reinforced plastics (CFRP) to suffer from invisible impact damage, for which the identification of such damage is of great significance. For the purpose of damage localization, this paper proposes a minimum variance distortion-less response (MVDR) algorithm that employs linear array sensor. In addition, a near field signal model based on active Lamb wave is established and the propagation of Lamb wave is investigated in composite laminates through the method of simulation. Moreover, a damage imaging system is also set up for composites to verify the effectiveness of the MVDR algorithm. Besides, in the study, wavelet transform is used as well to extract narrowband signals and promote signal-to-noise. It is shown by the results that the proposed algorithm can accurately identify the location of damage through the method of imaging. It is concluded that the maximum error of damage identification is 1.2 cm and MVDR algorithm has great potential in the field, damage imaging of composite materials. As a result, it provides a novel idea for damage imaging of composite materials.

scholarly journals A Non-Destructive Imaging Method Based on Integral Signals of Ultrasonic Pulse

2021 ◽  
Vol 8 (1) ◽  
pp. 9-13
Author(s):  
Qiuhe Huang
Keyword(s):  
Phased Array ◽  
Matrix Decomposition ◽  
Pulse Signal ◽  
Laplacian Matrix ◽  
Ultrasonic Pulse ◽  
Inverse Laplace Transform ◽  
Imaging Method ◽  
Ultrasonic Phased Array ◽  
The Green Function ◽  
Array Imaging

For ultrasonic phased array imaging, the most popular technique is the delay superposition algorithm of time domain signals with fixed weights. However, this technique and similar approaches cannot effectively suppress the non-scanning azimuth noise, which drags the imaging resolution. To overcome the problem, this paper proposes a nondestructive imaging method based on ultrasonic pulse integral signal, on the basis of ultrasonic phased array imaging. This method relies on the Green function to implement inverse Laplace transform on the ultrasonic pulse signal, obtains the analytical expression of the operator through mathematical derivations and calculations, and adopts the eigenvalues obtained by Laplacian matrix decomposition for image edge detection. The experimental results show that the operator is simple and effective, and better in imaging than other methods.

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