Development of a non-contact stress measurement system during tensile testing using the electromagnetic acoustic transducer for a Lamb wave

In recent years, investigations into the changes in the microstructure of functional metal materials during their processing have been carried out by many researchers. Therefore, it is required that the change in the material characteristics during processing by a nondestructive evaluation method be evaluated. However, conventional technology has been restricted to a static material characteristic evaluation. For example, a strain gauge has the problem that it can influence the measurement conditions of the tensile test and can only evaluate the position at which the strain gauge is attached. We then tried to develop a non-contact stress measurement system for tensile testing using an EMAT with a Lamb wave as the first step for the material characterization evaluation during mechanical testing. The EMAT measures the propagation time of a Lamb wave between the receiver and a transmitter during the tensile testing. The interval between the transmitter and the receiver of the first set is 10 mm and can move in the direction of the tensile load. In this presentation, the specifications of the measurement system and the evaluation results are reported.