Experimental study of guided waves propagation characteristics under the changing temperatures

Abstract

Structural Health Monitoring (SHM) plays an important role in ensuring the safe use of aerospace, architecture and other fields. At present, SHM based on piezoelectric and guided waves is a hot spot for real-time monitoring and nondestructive testing. However, the effect of environmental temperatures may mask the signal changes caused by damage and lead to failure of guided wave SHM methods. In this paper, the influence mechanism of the changing temperatures on the propagation characteristics of the guided wave is analyzed. Piezoelectric constants changed with the changing temperatures due to the amplitude variation of the guided wave with the changing temperatures. The effect of temperature on material properties of the plate structures will result in the influence of the guided wave propagation speed. An experiment is performed to study the propagation characteristics of the guided wave on an aluminium plate under changing temperatures. The experimental results indicate that the temperature can change the guide wave amplitude and velocity. At the same time, the temperature effect has the same variation trend at different frequencies, and the slopes of the linear fitting of the propagation characteristics of guided waves with the changing temperatures are also almost consistent.