A method of acoustic emission source location for engine fault based on time difference matrix

Abstract

The structure of a high-performance engine is becoming more and more complex, so it is very important to accurately and quickly locate the faults to ensure its operation safety. The acoustic emission (AE) signal which is caused by the structural damage of engines contains important structural integrity information; however, the accuracy of existing AE location methods is affected by complex structures, such as stiffeners, holes, variable wall thickness, and interface coupling. Therefore, this paper proposes a new AE source location method that combines the two-step Akaike information criterion (AIC) based on the dispersion curve and the time difference matrix (TDM). This method can precisely locate the faults of complex structures without considering the wave velocity. Through theoretical calculation and numerical simulation, this paper intends to show that the proposed method is superior to the traditional AIC and can track the arrival time of the AE signal more accurately. In addition, experiments on different structures illustrate that the proposed method has higher location accuracy in complex structures. This paper also analyzes the location sensitivity to the number and array of sensors in a complex structure and puts forward an optimal scheme of sensor layout on the condition of high location accuracy. The results show that the proposed method can be used as a reliable tool for AE source location and fault monitoring of complex structures. It will have a wide application prospect in the engine and other fields.