Effects of Apparatus Parameters on MFL Signals Using Orthogonal Experimental Design

2010 ◽  
Vol 44-47 ◽  
pp. 3524-3528 ◽  
Author(s):  
Qiang Song
Keyword(s):  
Experimental Design ◽  
Orthogonal Experimental Design ◽  
Preparation Technique ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Method ◽  
Sample Preparation Technique ◽  
Series Of Experiments ◽  
Non Destructive ◽  
Flux Leakage

Magnetic flux leakage (MFL) is a non-destructive testing method used to inspect ferrous materials. However, there are a variety of factors that can affect the MFL inspection tool’s ability to detect and characterize anomalies. An orthogonal experimental design (OED) method is applied to study the effects of apparatus parameters on MFL signals. Integration of OED method of analysis into a routine sample preparation technique could improve the repeatability and quantization capabilities of MFL tools. Three key apparatus parameters, namely permanent magnet (PM) height, magnetic concentrator (MC) length and backing iron (BI) length are chosen for the present study. The importance of each of these key parameters on MFL signals for different defects is determined by a series of experiments.

scholarly journals Magnetic Flux Leakage Course of Inner Defects and Its Detectable Depth

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jianbo Wu ◽  
Wenqiang Wu ◽  
Erlong Li ◽  
Yihua Kang
Keyword(s):  
Magnetic Flux ◽  
Steel Structure ◽  
High Sensitivity ◽  
Magnetic Flux Leakage ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Near Surface ◽  
Testing Method ◽  
Non Destructive ◽  
Flux Leakage

AbstractAs a promising non-destructive testing (NDT) method, magnetic flux leakage (MFL) testing has been widely used for steel structure inspection. However, MFL testing still faces a great challenge to detect inner defects. Existing MFL course researches mainly focus on surface-breaking defects while that of inner defects is overlooked. In the paper, MFL course of inner defects is investigated by building magnetic circuit models, performing numerical simulations, and conducting MFL experiments. It is found that the near-surface wall has an enhancing effect on the MFL course due to higher permeability of steel than that of air. Further, a high-sensitivity MFL testing method consisting of Helmholtz coil magnetization and induction coil with a high permeability core is proposed to increase the detectable depth of inner defects. Experimental results show that inner defects with buried depth up to 80.0 mm can be detected, suggesting that the proposed MFL method has the potential to detect deeply-buried defects and has a promising future in the field of NDT.

Effects of Magnetic Concentrator on MFL Signals Using FEA

2011 ◽  
Vol 204-210 ◽  
pp. 1956-1959
Author(s):  
Qiang Song
Keyword(s):  
Signal To Noise Ratio ◽  
Axial Component ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Element Analysis ◽  
Leakage Flux ◽  
Testing Method ◽  
Detection Schemes ◽  
Non Destructive ◽  
Flux Leakage

Magnetic flux leakage (MFL) is a non-destructive testing method used to inspect ferrous materials. However, there are a variety of factors that can affect the MFL inspection tool’s ability to detect and characterize anomalies. MFL signals obtained during the inspection of pipes have been simulated using 3D finite element analysis (FEA) and the effects of magnetic concentrator on MFL signals are investigated. Measurements of the leakage flux with various defect depths or widths indicate that the axial component of MFL are improved by magnetic concentrator with the result that significant advantages could be obtained in defect detection schemes, in that the signal to noise ratio (SNR) of MFL signals can be improved by magnetic concentrator.

Application of Gradient Based IR Thermography to the GRP Structures Inspection

2011 ◽  
Vol 488-489 ◽  
pp. 682-685 ◽  
Author(s):  
Lovre Krstulović-Opara ◽  
Endri Garafulić ◽  
Branko Klarin ◽  
Željko Domazet
Keyword(s):  
Pulse Heating ◽  
Non Destructive Testing ◽  
Ir Thermography ◽  
Destructive Testing ◽  
Heat Flows ◽  
Testing Method ◽  
Reinforced Polymer ◽  
Gradient Based ◽  
Non Destructive ◽  
Gradient Approach

The article presents application of non destructive testing method based on the pulse heating infrared thermography used to detect material anomalies for the case of glass reinforced polymer structures. The goal of presented research, based on the thermal gradient approach, is to establish the procedure capable of filtering out anomalies from other thermal influences caused by thermal reflections of surrounding objects, geometry influences and heat flows for observed object.

A New Non-destructive Testing Method Applied to Clinching

2021 ◽  
pp. 1461-1468
Author(s):  
Rémi Lafarge ◽  
Alexander Wolf ◽  
Christina Guilleaume ◽  
Alexander Brosius
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Method ◽  
Non Destructive

A Non-Destructive Testing Method and Analysis for Air Pressure Distribution in the Stacks of Building Drainage Systems

2008 ◽  
Author(s):  
Cheng-Li Cheng ◽  
Wan-Ju Liao ◽  
Kuen-Chi He ◽  
Chia-Ju Yen
Keyword(s):  
Pressure Fluctuation ◽  
Drainage System ◽  
Field Testing ◽  
Air Pressure ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Drainage Systems ◽  
Existing Building ◽  
Testing Method ◽  
Non Destructive

A drainage system is one of the most essential facilities in building service engineering. Unfortunately relevant technology used today to analyze it was developed decades ago. This research investigated the case of existing building drainage systems in Taiwan, including our previous studies. The purpose of this paper is the development of a non-destructive testing method of air pressure fluctuation in a stacked building drainage system using field observation and experimental study of stack fluid mechanisms. A portable testing device is developed to execute field testing in existing drainage systems to determine air pressure fluctuation in the stacks of buildings. Meanwhile, the Fourier Transform Process is adopted in this paper to analyze the power spectrum of air pressure fluctuation in a drainage stack and to verify the previous theoretical study. Validation obtained from case-studies can be used to confirm the practicality of this portable and non-destructive testing method. As a result, the proposed testing method can be applied to the diagnosis of existing building drainage systems and improve the design of a drainage system in an existing housing complex.

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