Comparison of coverage areas of two different sensor network arrangements for structural health monitoring of plate-like structures

In the last decade, Lamb wave based structural health monitoring (SHM) has been gaining attention for real-time monitoring of plate-like structures. Although the capabilities of Lamb wave in detecting cracks in metallic plates have been studied and proven, there is not a systematic method explaining how to predict network coverage of a sparse array of sensors to send and receive Lamb waves. In this study, initial steps are taken to simulate and predict coverage area of simple sensor network configurations for detecting a specific type of under-surface crack. Computer models are developed for Lamb wave propagation simulation using Finite Element Method (FEM). Using the models, an initial framework is developed to estimate coverage area of a sensor network to detect one type of under-surface crack. Using the framework, coverage area of three different simple sensor arrangements to detect horizontal cracks in an aluminum plate is estimated. The first arrangement is a single transducer, whereas the two other arrangements consist of two and three transducers/sensors respectively. Coverage area is increased as number of transducers in the sensor network is increased.