A two-dimensional eddy current array–based sensing film for estimating failure modes and tracking damage growth of bolted joints

2019 ◽  
pp. 147592171984306 ◽  
Author(s):  
Hu Sun ◽  
Tao Wang ◽  
Qijian Liu ◽  
Yishou Wang ◽  
Xinlin Qing
Keyword(s):  
Eddy Current ◽  
Failure Modes ◽  
Bolted Joints ◽  
Two Dimensional ◽  
Damage Growth

On-site monitoring of bearing failure in composite bolted joints using built-in eddy current sensing film

2020 ◽  
pp. 002199832097973
Author(s):  
Qijian Liu ◽  
Hu Sun ◽  
Yuan Chai ◽  
Jianjian Zhu ◽  
Tao Wang ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Eddy Current ◽  
Failure Modes ◽  
Bolted Joints ◽  
Bearing Failure ◽  
Monitoring Method ◽  
Current Sensing ◽  
Site Monitoring ◽  
Array Sensing ◽  
Bearing Damage

Bearing damage is one of the common failure modes in composite bolted joints. This paper describes the development of an on-site monitoring method based on eddy current (EC) sensing film to monitor the bearing damage in carbon fiber reinforced plastic (CFRP) single-lap bolted joints under tensile testing. Configuration design and operating principles of EC array sensing film are demonstrated. A series of numerical simulations are conducted to analyze the variation of EC when the bearing failure occurs around the bolt hole. The results of damage detection in the horizontal direction and through the thickness direction in the bolt hole with different exciting current directions are presented by the finite element method (FEM). Experiments are performed to prove the feasibility of the proposed EC array sensing film when the bearing failure occurs in CFRP single-lap bolted joints. The results of numerical simulations and experiments indicate that bearing failure can be detected according to the variation of EC in the test specimen.

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 A Two-Dimensional Model for Pin-Load Distribution and Failure Analysis of Composite Bolted Joints

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3646
Author(s):  
Binkai Li ◽  
Yu Gong ◽  
Hao Xiao ◽  
Yukui Gao ◽  
Enquan Liang
Keyword(s):  
Load Distribution ◽  
Failure Modes ◽  
Failure Prediction ◽  
Element Model ◽  
Bolted Joints ◽  
Distribution Analysis ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Material Stiffness ◽  
Two Dimensional Model

Multibolt composite joints are widely used in aircraft structures. The determination of the pin-load distribution among the bolts is a critical step in the failure prediction of bolted joints. In this paper, a two-dimensional model of the multibolt composite structure is established for the pin-load distribution analysis. Its accuracy is validated by experimental results and the results from a 3D finite element model. Based on the determined pin-load distribution, FE models for a laminated plate with three-row fastener joints are built for failure prediction. Hashin stress criteria and the degradation guidelines of the material stiffness with respect to the different failure modes proposed by Tserpes are applied for the failure evaluation and the material degradation, respectively. The failure location and ultimate load are well predicted, which further validates the effectiveness and applicability of the proposed model for the pin-load distribution analysis.

scholarly journals Composite hollow truss with multiple vierendeel panels

2013 ◽  
Vol 66 (4) ◽  
pp. 431-438
Author(s):  
Augusto Ottoni Bueno da Silva ◽  
Newton de Oliveira Pinto Júnior ◽  
João Alberto Venegas Requena
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Three Dimensional ◽  
Analytical Calculation ◽  
Two Dimensional ◽  
Shear Forces ◽  
Vertical Displacements ◽  
New System ◽  
The Ideal

The aim of this study was to evaluate through analytical calculation, two-dimensional elastic modeling, and three-dimensional plastic modeling, the bearing capacity and failure modes of composite hollow trusses bi-supported with a 15 meter span, varying the number of central Vierendeel panels. The study found the proportion span/3 - span/3 - span/3, as the ideal relationship for the truss - Vierendeel - truss lengths, because by increasing the proportion of the length occupied by the central Vierendeel panels, the new system loses stiffness and no longer supports the load stipulated in the project. Furthermore, they can start presenting excessive vertical displacements and insufficient resistance to external shear forces acting on the panels.

Two Dimensional Multi-Frequency Eddy Current Data Fusion

1996 ◽  
pp. 2125-2132 ◽  
Author(s):  
M. Mina ◽  
J. Yim ◽  
S. S. Udpa ◽  
L. Udpa ◽  
W. Lord ◽  
...  
Keyword(s):  
Data Fusion ◽  
Eddy Current ◽  
Current Data ◽  
Two Dimensional

Response of Resin Transfer Molded (RTM) Composites Under Reversed Cyclic Loading

1996 ◽  
Vol 118 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Hassan Mahfuz ◽  
Anwar Haque ◽  
Daixu Yu ◽  
Shaik Jeelani
Keyword(s):  
Failure Modes ◽  
Load Level ◽  
Failure Behavior ◽  
Progressive Damage ◽  
Damage Growth ◽  
Static Tests ◽  
Strength And Stiffness ◽  
Reversed Cyclic ◽  
Fatigue Failures ◽  
Circular Notch

Compressive behavior and the tension-compression fatigue response of resin transfer molded IM7 PW/PR 500 composite laminate with a circular notch have been studied. Fatigue damage characteristics have been investigated through the changes in the laminate strength and stiffness by gradually incrementing the fatigue cycles at a preselected load level. Progressive damage in the surface of the laminate during fatigue has been investigated using cellulose replicas. Failure mechanisms during static and cyclic tests have been identified and presented in detail. Extensive debonding of filaments and complete fiber bundle fracture accompanied by delamination were found to be responsible for fatigue failures, while fiber buckling, partial fiber fracture and delamination were characterized as the failure modes during static tests. Weibull analysis of the static, cyclic and residual tests have been performed and described in detail. Fractured as well as untested specimens were C-scanned, and the progressive damage growth during fatigue is presented. Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) for the fractured specimen were also performed and the analysis of the failure behavior is presented.

Stress Analysis and the Characteristics of T-Shape Bolted Joints Under Tensile Loadings

2005 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Seiichi Hamamoto
Keyword(s):  
Bending Moment ◽  
Theory Of Elasticity ◽  
Bolted Joints ◽  
Load Factor ◽  
Two Dimensional ◽  
Bolted Joint ◽  
Dimensional Theory ◽  
Matching Method ◽  
Point Matching ◽  
Bolt Stress

In designing a bolted joint, it is important to examine the interface stress distribution (clamping effect) and to estimate the load factor, that is the ratio of an additional axial bolt force to a load. In order to improve the clamping effect raised faces of the interface have been used. But these interfaces in bolted joints have been designed empirically and the theoretical grounds are not made clear. In the present paper, in the case of T-shaped flanges with raised faces the clamping effect is analyzed by a two-dimensional theory of elasticity and the point matching method. Then, the load factor is analyzed. Moreover, with the application of the load a bending moment is occurred in bolts and the stress is added due to this bending moment. The bending moment in the bolt is also analyzed. In order to verify these analyses experiments to measure the load factor and the maximum bolt stress were carried out. The values of the load factor and the load when interface start to separate are compared with those of the joints with flat-faces. The analytical results are in fairly good agreements with the experimental ones.

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