A new interleaving eddy current array-based sensing film for fatigue crack quantification of bolted joints

2021 ◽  
pp. 1045389X2199089
Author(s):  
Hu Sun ◽  
Junyan Yi ◽  
Tao Wang ◽  
Yishou Wang ◽  
Xinlin Qing
Keyword(s):  
Fatigue Crack ◽  
Eddy Current ◽  
Edge Crack ◽  
Crack Detection ◽  
Structural Integrity ◽  
Bolted Joints ◽  
Induced Voltage ◽  
Coil Array ◽  
Hole Edge ◽  
Crack Angle

Fatigue crack quantification for bolted joints attracts much attention to determine the structural integrity for aircraft structures. In this paper, a new sensing film with interleaving eddy current array is proposed to evaluate the parameters of the hole-edge crack for single- or multiple-lap bolted joints. In this sensing film, the exciting layer is one coil throughout the hole wall which consists of a one-dimension rectangle coil array in the axial direction connecting in series, while the sensing layer is made up of two interleaving layers with a two-dimensional sensing coil array distributed in the circumferential and axial directions for each layer. Finite element simulation is conducted to study the effect of different crack parameters on the induced voltage of sensing coils. Simulation results reveal that the sensing film has no blind angle of crack detection but a strong capability of quantifying the crack angle, and the arctangent value of the ratio between interleaving coils can be used for estimating the crack angle. After the crack angle is estimated, induced voltages of sensing coils at this angle may be used to track the crack propagation in the axial or radial directions of the bolt hole. Experiments are conducted to verify the feasibility and effectiveness of the new sensing film to monitor the angle, depth, and length of the hole-edge crack of bolted joints.

scholarly journals On-Site Health Monitoring of Composite Bolted Joint Using Built-In Distributed Eddy Current Sensor Network

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2785 ◽  
Author(s):  
Qijian Liu ◽  
Hu Sun ◽  
Tao Wang ◽  
Xinlin Qing
Keyword(s):  
Numerical Simulation ◽  
Sensor Network ◽  
Eddy Current ◽  
Failure Modes ◽  
Unidirectional Composite ◽  
Bolted Joints ◽  
Induced Voltage ◽  
Hole Edge ◽  
Exciting Coil ◽  
Array Sensing

There is an urgent need to monitor the structural state of composite bolted joints while still remaining in service; however, there are many difficulties in analyzing their strength and failure modes. In this paper, a built-in distributed eddy current (EC) sensor network based on EC array sensing film is developed to monitor the hole-edge damages of composite bolted joints. The EC array sensing film is bonded onto the bolt and consists of one exciting coil and four separate sensing coils. Experiments are conducted on unidirectional composite specimens to validate the ability of the EC array sensing film to quantitatively track the damage that occurs at the hole edge and to investigate the performances of the EC array sensing films with different configurations of the exciting coil. Experimental results show that the induced voltage of sensing coil changes only if the damage appears on the laminate structure where that particular sensing coil is located, whereas the induced voltages of the other sensing coils on other laminate plates remain unchanged. Numerical simulation based on the finite element method is also carried out to investigate and explain the phenomena observed in the experiments and to analyze the distribution of the EC around the bolt hole. Both experimental and numerical simulation results demonstrate that the developed EC array sensing film can effectively identify not only whether there is damage at the hole edge but also the damage location within the thickness and quantitative size.

scholarly journals Quantifying Hole-Edge Crack of Bolt Joints by Using an Embedding Triangle Eddy Current Sensing Film

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2567
Author(s):  
Shilei Fan ◽  
Junyan Yi ◽  
Hu Sun ◽  
Fenglin Yun
Keyword(s):  
Eddy Current ◽  
Edge Crack ◽  
Sensor Array ◽  
Structural Integrity ◽  
Crack Depth ◽  
The Novel ◽  
Current Sensing ◽  
Hole Edge ◽  
Good Potential ◽  
Excitation Winding

Hole-edge crack quantification of bolt joints is critical for monitoring and estimating structural integrity of aircraft. The paper proposes a new triangle eddy current sensor array for the purpose of increasing the level of quantifying hole-edge crack parameters, especially, the crack angle. The new senor array consists of triangular coils instead of planar rectangular coils. The configuration of the novel sensor array, including the excitation current directions and the excitation winding shape, is optimized by simulation. The ability of the proposed sensing film to identify the crack parameters has been verified by finite element simulations and experiments. Results shows that triangular coils with same current directions in circumferentially adjacent coils and opposite current directions in axially adjacent coils achieve better performance in sensor linearity and resolution compared to rectangular coils. In addition, it has also been proved that the sensing film has a good potential to identify the crack depth and length.

scholarly journals The early stage wheel fatigue crack detection using eddy current pulsed thermography

2017 ◽  
Author(s):  
Jianping Peng ◽  
Kang Zhang ◽  
Kai Yang ◽  
Zhu He ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Eddy Current ◽  
Crack Detection ◽  
Early Stage ◽  
Pulsed Thermography ◽  
Fatigue Crack Detection

scholarly journals In-Line Inspection Tool with Eddy Current Instrumentation for Fatigue Crack Detection

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2161 ◽  
Author(s):  
Cesar Camerini ◽  
João Rebello ◽  
Lucas Braga ◽  
Rafael Santos ◽  
Tomasz Chady ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Eddy Current ◽  
Crack Detection ◽  
Fatigue Crack Detection

scholarly journals An Eddy Current-Based Structural Health Monitoring Technique for Tracking Bolt Cracking

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6843
Author(s):  
Hu Sun ◽  
Tao Wang ◽  
Dawei Lin ◽  
Yishou Wang ◽  
Xinlin Qing
Keyword(s):  
Structural Health Monitoring ◽  
Eddy Current ◽  
Health Monitoring ◽  
Large Scale ◽  
Crack Depth ◽  
Structural Safety ◽  
Induced Voltage ◽  
Coil Array ◽  
Structural Health ◽  
Monitoring Technique

Bolted joints are the primary structures for the load transfer of large-scale structures. It is vital to monitor the process of bolt cracking for enduring structural safety. In this paper, a structural health monitoring technique based on the embedding eddy current sensing film has been proposed to quantify the crack parameters of bolt cracking. Two configurations of the sensing film containing one-dimensional circumferential coil array and two-dimensional coil array are designed and verified to have the ability to identify three crack parameters: the crack angle, the crack depth, and the crack location in the axial direction of the bolt. The finite element method has been employed not only to verify the capacity of the sensing film, but also to investigate the interaction between the crack and the eddy current/magnetic field. It has been demonstrated that as the crack propagates, the variations of the induced voltage of the sensing coils are influenced by both eddy current effect and magnetic flux leakage, which play different roles in the different periods of the crack propagation. Experiments have been performed to verify the effectiveness and feasibility of the sensing film to quantify three crack parameters in the process of the bolt cracking.

A one-dimensional approach towards edge crack detection and mapping using eddy current thermography

2020 ◽  
Vol 309 ◽  
pp. 111999
Author(s):  
Natali Barakat ◽  
Jafar Mortadha ◽  
Ali Khan ◽  
Bassam A. Abu-Nabah ◽  
Mohammad O. Hamdan ◽  
...  
Keyword(s):  
Eddy Current ◽  
Edge Crack ◽  
Crack Detection ◽  
Dimensional Approach ◽  
One Dimensional
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