Nonlinear Lamb waves for fatigue damage identification in FRP-reinforced steel plates

Ultrasonics ◽  
2017 ◽  
Vol 80 ◽  
pp. 87-95 ◽  
Author(s):  
Yikuan Wang ◽  
Ruiqi Guan ◽  
Ye Lu
Keyword(s):  
Fatigue Damage ◽  
Damage Identification ◽  
Lamb Waves ◽  
Steel Plates ◽  
Reinforced Steel

scholarly journals Wave Frequency Effects on Damage Imaging in Adhesive Joints Using Lamb Waves and RMS

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1842 ◽  
Author(s):  
Erwin Wojtczak ◽  
Magdalena Rucka
Keyword(s):  
Damage Identification ◽  
Lamb Waves ◽  
Excitation Frequency ◽  
Visual Assessment ◽  
Adhesive Joints ◽  
Ultrasonic Waves ◽  
Steel Plates ◽  
Wave Frequency ◽  
Destructive Testing ◽  
Wide Range

Structural adhesive joints have numerous applications in many fields of industry. The gradual deterioration of adhesive material over time causes a possibility of unexpected failure and the need for non-destructive testing of existing joints. The Lamb wave propagation method is one of the most promising techniques for the damage identification of such connections. The aim of this study was experimental and numerical research on the effects of the wave frequency on damage identification in a single-lap adhesive joint of steel plates. The ultrasonic waves were excited at one point of an analyzed specimen and then measured in a certain area of the joint. The recorded wave velocity signals were processed by the way of a root mean square (RMS) calculation, giving the actual position and geometry of defects. In addition to the visual assessment of damage maps, a statistical analysis was conducted. The influence of an excitation frequency value on the obtained visualizations was considered experimentally and numerically in the wide range for a single defect. Supplementary finite element method (FEM) calculations were performed for three additional damage variants. The results revealed some limitations of the proposed method. The main conclusion was that the effectiveness of measurements strongly depends on the chosen wave frequency value.

scholarly journals Damage Identification of Large Generator Stator Insulation Based on PZT Sensor Systems and Hybrid Features of Lamb Waves

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2745 ◽  
Author(s):  
Ruihua Li ◽  
Hao Li ◽  
Bo Hu
Keyword(s):  
Power Systems ◽  
Lamb Wave ◽  
Damage Identification ◽  
Lamb Waves ◽  
Fem Simulation ◽  
Correlation Coefficients ◽  
Hybrid Features ◽  
Material Inhomogeneity ◽  
Time Frequency ◽  
Damage Imaging

Large generators are the principal pieces of equipment in power systems, and their operation reliability critically depends on the stator insulation. Damages in stator insulation will gradually lead to the failure and breakdown of generator. Due to the advantages of Lamb waves in Structural health monitoring (SHM), in this study, a distributed piezoelectric (PZT) sensor system and hybrid features of the Lamb waves are introduced to identify stator insulation damage of large generator. A hierarchical probability damage-imaging (PDI) algorithm is proposed to tackle the material inhomogeneity and anisotropy of the stator insulation. The proposed method includes three steps: global detection using correlation coefficients, local detection using Time of flight (ToF) along with the amplitude of damage-scattered Lamb wave, and final images fusion. Wavelet Transform was used to extract the ToF of Lamb wave in terms of the time-frequency domain. Finite Element Modeling (FEM) simulation and experimental work were carried out to identify four typical stator insulation damages for validation, including inner void, inner delamination, puncture, and crack. Results show that the proposed method can precisely identify the location of stator insulation damage, and the reconstruction image can be used to identify the size of stator insulation damage.

Locating fatigue damage using temporal signal features of nonlinear Lamb waves

2015 ◽  
Vol 60-61 ◽  
pp. 182-197 ◽  
Author(s):  
Ming Hong ◽  
Zhongqing Su ◽  
Ye Lu ◽  
Hoon Sohn ◽  
Xinlin Qing
Keyword(s):  
Fatigue Damage ◽  
Lamb Waves ◽  
Signal Features

Early Fatigue Damage Evaluation of Nonlinear Guided Wave Imaging in Hyperelastic Materials

2021 ◽  
Author(s):  
Chengwei Zhao ◽  
Sunia Tanweer ◽  
Jian Li ◽  
Min Lin ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Fatigue Damage ◽  
Guided Waves ◽  
Lamb Waves ◽  
Tone Burst ◽  
Guided Wave ◽  
Third Order ◽  
Hyperelastic Materials ◽  
Third Order Elastic Constants ◽  
Wave Imaging ◽  
Processing Platform

Abstract Nonlinear ultrasonic guided waves have superior sensitivity of the early fatigue damage. This paper investigates 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. The Murnaghan’s model is implemented in a finite element (FE) analysis to describe the hyperelastic constitutive relation for nonlinear acoustic modeling. The second harmonics of s0 mode are actuated by a 60kHz Hanning-windowed tone burst. A guided wave signal processing platform is developed for tomographic imaging. The different stages of fatigue are reflected by the changes of third-order elastic constants (TOECs) in Murnaghan’s model. The reconstructed damage locations match well with the actual ones cross different degrees and depths of fatigue.

scholarly journals Detection of debonding in adhesive joints using Lamb wave propagation

2019 ◽  
Vol 262 ◽  
pp. 10012
Author(s):  
Magdalena Rucka ◽  
Erwin Wojtczak ◽  
Jacek Lachowicz
Keyword(s):  
Wave Propagation ◽  
Lamb Waves ◽  
Visual Assessment ◽  
Guided Wave ◽  
Steel Plates ◽  
Experimental Investigations ◽  
Mechanical Degradation ◽  
Adhesively Bonded ◽  
Destructive Testing ◽  
Out Of Plane

Adhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form of partial debonding) were prepared. The inspection was conducted with the use of guided wave propagation method. Lamb waves were excited at one point of the sample, whereas the out-of-plane velocity signals were recorded in a number of points spread over the area of overlap. The processing of signals consisted of calculations of weighted root mean square (WRMS). The results of the analysis showed that the WRMS maps allow for identification and determination of size and shape of debonding areas.

Damage Identification by Embedded Piezoceramic Sensors in the Composite Plate

2006 ◽  
Vol 326-328 ◽  
pp. 1697-1700
Author(s):  
Heoung Jae Chun ◽  
Choong Hee Yi ◽  
Joon Hyung Byun
Keyword(s):  
Monitoring System ◽  
Health Monitoring ◽  
Composite Laminates ◽  
Damage Identification ◽  
Lamb Waves ◽  
Structural Systems ◽  
Detection Accuracy ◽  
Health Monitoring System ◽  
Localized Defects ◽  
The Many

The embedded structural health monitoring system is envisioned to be an important factor of future structural systems. One of the many attractions of in situ health monitoring system is its capability to inspect the structural systems in less intrusive way over many other visual inspections which require disassembly of built up structures when some indications have appeared that damages have occurred in the structural systems The vacuum assisted resin transfer molding (VARTM) process is used to fabricate woven-glass/phenol composite specimens which have the PZT sensor array embedded in them. The embedded piezoceramic (PZT) sensors are used as both transmitters and receivers. A damage identification approach is developed for a woven-glass/phenol composite laminates with known localized defects. Propagation of the Lamb waves in laminates and their interactions with the defects are examined. Lamb waves are generated by the high power ultrasonic analyzer. A real time active diagnosis system is therefore established. The results obtained show that satisfactory detection accuracy could be achieved by proposed method.

A feasibility study on fatigue damage evaluation using nonlinear Lamb waves with group-velocity mismatching

Ultrasonics ◽  
2018 ◽  
Vol 90 ◽  
pp. 18-22 ◽  
Author(s):  
Wujun Zhu ◽  
Yanxun Xiang ◽  
Chang-Jun Liu ◽  
Mingxi Deng ◽  
Fu-Zhen Xuan
Keyword(s):  
Group Velocity ◽  
Fatigue Damage ◽  
Feasibility Study ◽  
Lamb Waves ◽  
Damage Evaluation

scholarly journals Research on Fatigue Damage in High-Strength Steel (FV520B) Using Nonlinear Ultrasonic Testing

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Bingbing Chen ◽  
Chao Wang ◽  
Pengfei Wang ◽  
Sanlong Zheng ◽  
Weiming Sun
Keyword(s):  
Fatigue Damage ◽  
High Strength Steel ◽  
Main Crack ◽  
Lamb Waves ◽  
High Strength ◽  
Nonlinear Parameter ◽  
Damage State ◽  
Nonlinear Parameters ◽  
Highly Sensitive ◽  
Nonlinear Ultrasonic

In view of the early fatigue damage of high-strength steel FV520B, a nonlinear ultrasonic detection was performed on two types of fatigue samples using nonlinear Lamb waves. The experimental results indicated that the ultrasonic nonlinear parameter is highly sensitive to early fatigue damage in high-strength FV520B. For plate specimens, the ultrasonic nonlinear parameter increased with the number of fatigue cycles. Scanning electron microscopy (SEM) observations of the fatigue specimens revealed that as the number of fatigue cycles increased, the microstructure of the material gradually deteriorated, and the ultrasonic nonlinear parameter increased. For notched specimens, the ultrasonic nonlinear parameter increased as the size of the main crack increased. SEM observations of the fracture indicated that the ultrasonic nonlinear parameters were more consistent with the equivalent microcrack length (defined as the sum of microcrack lengths in the statistical area), as compared with the length of the main crack. It was determined that the nonlinear effect of the Lamb wave is related to the equivalent microcrack length inside the material and that the ultrasonic nonlinear parameter can effectively characterize the fatigue damage state of high-strength FV520B.

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