Finite element modeling of crack detection in aircraft structures using electrical current

Abstract

Various non-destructive test methods have been developed for the detection of cracks in metallic structures. Electromagnetic non-destructive testing (NDT) is one of the widely used non-destructive methods used for the detection and characterization of cracks. Utilizing the principle of electromagnetic induction, this technique is used in the areas of nuclear, aerospace, power, transport, petroleum and other industries to inspect defects in metallic sheets, plates and tubes that have good electrical conductivity.;Aircraft structures and wings are made of aluminum sheets riveted together. Cracks are often found emanating from the edge of the rivet holes which are covered by the rivets and are difficult to be detected. Electromagnetic NDT, which involves flow of electrical current and a resultant magnetic field, can be applied to detect these cracks.;In this research, a finite element model was developed which utilizes the principle of electromagnetic NDT. Electrical current density analyses were carried out on aluminum plate with cracks of various shapes and sizes, and demonstrated how electromagnetic NDT can help detect cracks emanating from edge of rivet holes