Numerical Simulation Study on Propagation Law of Acoustic Emission Signal of Slewing Ring

摘要

Based on the explicit dynamic analysis method, finite element model of acoustic emission signal propagation of slewing ring is created by using ANSYS/ LS-DYNA software, processing acoustic emission signal as a kind of high frequency stress wave. The propagation law of acoustic emission signal of slewing outer ring is respectively studied from four aspects: amplitude, frequency, energy, and propagation path. The results show that time-domain waveform of acoustic emission signal is distorted through propagating due to the complexity of the propagation path, and frequency components of the signal are dispersed and energy is attenuated at the same time. Compared with the upper and lower surfaces of slewing outer ring, the form of signal energy attenuation of outer surface is relatively simple and can be described as an exponential decay. Therefore, the outer surface is suitable for installing sensors and signal acquisition in the course of acoustic emission testing; however, taking the impact of signal distortion into account, the number of the sensors used in acquisition should not be less than three.