Influence of Fe2O3 Content on Acoustic Properties of Backing Materials and Development and Utilization of Acoustic Emission Sensors

Abstract

Fe2O3 and epoxy resin sensor substrate materials (Fe2O3/epoxy resin composite material) are prepared in this article. A series of acoustic emission sensors are prepared by using composite material as sensor substrate, and the effect of Fe2O3 content in composite material on sensor performance is studied. The effect of Fe2O3 content in the composite material on the performance of the sensor is studied through the simulated lead‐breaking experiment, and the self‐made sensor is calibrated by using the calibration system. Nondestructive testing of concrete materials with different strengths is carried out by selecting the sensor with the best performance. The results show that the content of Fe2O3 in the composite increases to 50%, the epoxy resin matrix reaches saturation point of accommodate Fe2O3 powder, and the propagation velocity of ultrasonic waves reaches the lowest point when it passes through the composite. The sensor with 50% Fe2O3 content as a backing layer has the highest sensitivity and signal‐to‐noise ratio. The relationship between the strength of concrete material and acoustic attenuation and frequency is established by using this sensor, and the law can be used to evaluate the strength and mechanical properties of concrete material without destroying them.