TY - JOUR

T1 - Using a Magnetic Flux Leakage Method to Evaluate Gaps in Railroad Bolt Joints

AU - Антипов, Андрей Геннадьевич

AU - Markov, A.

AU - Maximova, E.

PY - 2023/6/1

Y1 - 2023/6/1

N2 - Abstract: Periodic evaluation of gaps in bolt joints of rails allows one to predict the reliability of a continuous welded rail track and prevent its temperature deformations. The purpose of the research is to find a simple and reliable way to evaluate joint gaps; this allows determining the gap values during high-speed inspection in automatic mode over a wide temperature range. A brief overview of technical solutions and methods for evaluating joint gaps based on various physical principles is given. The proposed technique uses the magnetic flux leakage (MFL) method with the placement of electromagnets on the wheelset axles of a four-wheel bogie. Such magnetization systems are currently used on flaw-detector cars and provide a stable magnetic flux in tested rails. Using a three-dimensional magnetostatic model of a rail segment with a bolt joint, the characteristics of leakage fields are studied when the size of the joint gap varies over the entire practical range. The characteristics that are most sensitive to the gap change and by which its value can be determined are selected. For small gap values, it is proposed to use the amplitude of the magnetic sensor signal as an informative parameter and for large gaps, the distance between signal extrema. The results of computer modeling of the effect of the joint gap size on the parameters of a magnetic sensor signal due to the gap qualitatively coincide with the results of field measurements performed at testing speeds of up to 60 km/h.

AB - Abstract: Periodic evaluation of gaps in bolt joints of rails allows one to predict the reliability of a continuous welded rail track and prevent its temperature deformations. The purpose of the research is to find a simple and reliable way to evaluate joint gaps; this allows determining the gap values during high-speed inspection in automatic mode over a wide temperature range. A brief overview of technical solutions and methods for evaluating joint gaps based on various physical principles is given. The proposed technique uses the magnetic flux leakage (MFL) method with the placement of electromagnets on the wheelset axles of a four-wheel bogie. Such magnetization systems are currently used on flaw-detector cars and provide a stable magnetic flux in tested rails. Using a three-dimensional magnetostatic model of a rail segment with a bolt joint, the characteristics of leakage fields are studied when the size of the joint gap varies over the entire practical range. The characteristics that are most sensitive to the gap change and by which its value can be determined are selected. For small gap values, it is proposed to use the amplitude of the magnetic sensor signal as an informative parameter and for large gaps, the distance between signal extrema. The results of computer modeling of the effect of the joint gap size on the parameters of a magnetic sensor signal due to the gap qualitatively coincide with the results of field measurements performed at testing speeds of up to 60 km/h.

KW - bolt joint

KW - continuous welded track

KW - joint gap

KW - magnetic flux leakage method

KW - magnetic sensor

KW - magnetizing system

KW - rail break

KW - rail non-destructive testing

UR - https://www.mendeley.com/catalogue/f15d8991-a6ab-3434-8a32-2171c84d4714/

U2 - 10.1134/S1061830923700420

DO - 10.1134/S1061830923700420

M3 - Article

VL - 59

SP - 677

EP - 690

JO - Russian Journal of Nondestructive Testing

JF - Russian Journal of Nondestructive Testing

SN - 1061-8309

IS - 6

ER -