Application of electromagnetic induction for impact load measurement

Abstract

Abstract In this paper, a small impact testing machine was developed as an application of the method for measuring impact load based on electromagnetic induction phenomena. The experimental results were shown to determine the effectiveness of the method. The electromotive forces generated in two coils near a specimen were measured when a small impactor containing a neodymium magnet, having a mass of 0.36 g, was dropped freely onto a 1.2-mm-thick glass plate. The histories of the impact load and the relation between the impact load and specimen deflection were evaluated from the measured electromotive forces because the electromotive force per impactor velocity is dependent on only the position of the impactor. The method and developed machine with the measurement system were determined to be effective by considering the experimental impact test results for the glass plates.