Defect characterisation in ferromagnetic and non-ferromagnetic aircraft plate materials using an electromagnetic acoustic transducer

Abstract

Non–destructive testing (NDT) is useful in aerospace industries for the maintenance of aircraft parts, such as thickness measurements, corrosion and defect detection in materials. The most common form of NDT is visual inspection and condition monitoring; however, in many situations, resources has to be made to use of special technique and instruments such as eddy current, magnetic particle radiography and ultrasonic. In this work, a finite element analysis of an electromagnetic acoustic transducer (EMAT) is presented. EMAT is an emerging technology that provides a non–contact process of testing materials compared with ultrasonic sensors that requires a coupling medium. The acoustic properties of the material are investigated, which involves the coupling of several physical parameters. An investigation of defect detection in ferromagnetic and non–ferromagnetic materials is conducted. Results obtained show that the model is capable of detecting defects in non–ferromagnetic and ferromagnetic plates of an aircraft using an EMAT.