Development of Small Drop Weight Testing Machine Based on Electromagnetic Induction Phenomenon

Abstract

In the paper, the small drop-weight testing machine was developed on the basis of electromagnetic induction phenomena. The electromotive force generated in the coil near the specimen was measured when the small impactor containing a neodymium magnet and having mass of 0.36, 0.44 or 0.63 g dropped on the specimen. The impact force and specimen deflection were analyzed from the measured electromotive force based on the facts that the electromotive-force intensity is proportional to the impactor velocity and the electromotive force variation is dependent on the impactor position according to Faraday's law of induction. The validities of the testing machine and measurement system were confirmed by considering the experimental results of the falling drop tests for the rubber plates.