Nondestructive Technique for the Determination of Cracks Parameters by Eddy Current in Differential Mode

Abstract

In this paper, a nondestructive technique is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks in materials and eventually to study their propagation using a crucial parameter such as the stress intensity factor. This approach has been used in the aircraft industry to control cracks. Besides, it makes it possible to highlight the defects of parts while preserving the integrity of the controlled products. On the other side, it highlights the reliability of the control of defects and gives convincing results for the improvement of the quality and the safety of the material.

Formulation for Stress Intensity Factors and J-Integral Calculation by Eddy Current Testing

“…(4) (5) This technique is employed when the model includes singular elements and where extrapolation can be done inside these elements in order to take into account the singularities they induce [17] 226…”

Eddy Current Sensor Modeling for the Nondestructive Evaluation of Stress Intensity Factor

“…SIF gives a measure of the intensity of the stress field in the crack tip region. It gives also the possibility to analyze a crack growth or a catastrophic failure if a load is applied to the structure [2]. The stress intensity factors can be calculated using stress and strain analysis or parameters that measure the energy released by crack growth.…”

Design and optimization of a flexible arrayed eddy current sensor

“…Another differential eddy current probe for measurement of thickness was developed, which consists of an excitation coil and two hall-sensors [16]. The differential eddy current sensors play an important role in the crack detection and sizing [17][18][19]. Li et al [20] developed a three-core probe and a U-shape probe with the close magnetic circuit for the concentration of the magnetic field.…”