Noncontact Air-Coupled Guided Wave Ultrasonics for Detection of Thinning Defects in Aluminum Plates

2001 ◽  
Vol 13 (1) ◽  
pp. 61-77 ◽  
Author(s):  
D. Tuzzeo ◽  
F. Lanza di Scalea
Keyword(s):  
Author(s):  
Zhaoyun Ma ◽  
Lingyu Yu

Abstract Noncontact and remote NDE systems and methods are highly desired in a broad range of engineering applications such as material property characterization. This paper aims to develop such a noncontact/remote NDE system based on laser ultrasonic guided waves and establish its fundamental capability for material thickness evaluation. The noncontact system employs pulsed laser (PL) for guided wave actuation and scanning laser Doppler vibrometer (SLDV) for guided wave wavefield sensing. A cylindrical planoconvex lens is adopted to focus the pulsed laser beam to a line source in order to excite broad band signals in the target plate. Aluminum plates with different thicknesses are evaluated through SLDV line scans and 2D time-space wavefields are acquired. Frequency-wavenumber (f-k) spectra are obtained through 2D Fourier transform, and the A0 dispersion curve for each plate is extracted. Through Comparing the extracted A0 curve with the theoretical A0 dispersion curves, the thicknesses of the tested plates are identified. Reflective tape effect on the plates are also studied: the reflective tape attached for SLDV enhancement affects the guided waves in the target plate significantly when the plate is relatively thin.


Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5498
Author(s):  
Chengwei Zhao ◽  
Sunia Tanweer ◽  
Jian Li ◽  
Min Lin ◽  
Xiang Zhang ◽  
...  

In this paper, the possibility of using nonlinear ultrasonic guided waves for early-life material degradation in metal plates is investigated through both computational modeling and study. The analysis of the second harmonics of Lamb waves in a free boundary aluminum plate, and the internal resonance conditions between the Lamb wave primary modes and the second harmonics are investigated. Subsequently, Murnaghan’s hyperelastic model is implemented in a finite element (FE) analysis to study the response of aluminum plates subjected to a 60 kHz Hanning-windowed tone burst. Different stages of material degradation are reflected as the changes in the third order elastic constants (TOECs) of the Murnaghan’s model. The reconstructed degradations match the actual ones well across various degrees of degradation. The effects of several relevant factors on the accuracy of reconstructions are also discussed.


2021 ◽  
Author(s):  
Clemens Grünsteidl ◽  
Georg Watzl ◽  
Christian Kerschbaummayr ◽  
Edgar Scherleitner ◽  
Günther Mayr ◽  
...  

Abstract We investigated roll-cladded aluminum structures consisting of a layer of Al4045 on Al3003 with a non-destructive laser-ultrasound technique. We determined the thickness of the cladding layer based on the dispersion of the fundamental guided wave propagating along the surface. We analyzed eight surfaces, with cladding thicknesses ranging from 0 to approximately 400μm The inversion of the dispersion data to obtain the thickness yielded in consistent results, which we compare to reference values obtained from micrographs. For the optimization procedure we allowed the material properties to be free parameters, but constrained them to be equal for all samples.


2009 ◽  
Vol 9 (2) ◽  
pp. 133-144 ◽  
Author(s):  
Dong Wang ◽  
Lin Ye ◽  
Zhongqing Su ◽  
Ye Lu ◽  
Fucai Li ◽  
...  

Ultrasonics ◽  
2015 ◽  
Vol 62 ◽  
pp. 203-212 ◽  
Author(s):  
Lingyu Yu ◽  
Zhenhua Tian ◽  
Cara A.C. Leckey

2020 ◽  
Vol 21 (5) ◽  
pp. 505
Author(s):  
Yousef Ghaderi Dehkordi ◽  
Ali Pourkamali Anaraki ◽  
Amir Reza Shahani

The prediction of residual stress relaxation is essential to assess the safety of welded components. This paper aims to study the influence of various effective parameters on residual stress relaxation under cyclic loading. In this regard, a 3D finite element modeling is performed to determine the residual stress in welded aluminum plates. The accuracy of this analysis is verified through experiment. To study the plasticity effect on stress relaxation, two plasticity models are implemented: perfect plasticity and combined isotropic-kinematic hardening. Hence, cyclic plasticity characterization of the material is specified by low cycle fatigue tests. It is found that the perfect plasticity leads to greater stress relaxation. In order to propose an accurate model to compute the residual stress relaxation, the Taguchi L18 array with four 3-level factors and one 6-level is employed. Using statistical analysis, the order of factors based on their effect on stress relaxation is determined as mean stress, stress amplitude, initial residual stress, and number of cycles. In addition, the stress relaxation increases with an increase in mean stress and stress amplitude.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 951-958
Author(s):  
Tianhao Liu ◽  
Yu Jin ◽  
Cuixiang Pei ◽  
Jie Han ◽  
Zhenmao Chen

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.


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