A virtual beam-like structure approach for fault diagnosis of complex structures

This paper proposes a new model-free method for fault diagnosis of complex structures based on the optimal vibration sensor chains. Energy transmission paths from the vibration source to every region of structure are studied for fault detection and fault isolation. Along the energy transmission path, the sensors are distributed as the networks on the complex structure. Each energy transmission path consisting of a created sensor chain is regarded as a virtual beam-like structure. By this way, the complex structure could be decomposed of some virtual beam-like structures and the fault diagnosis of the complex structure is then transformed as the fault diagnosis of some beam-like structures. This method is named as virtual beam-like structure approach. The novelty of the proposed method is that it has no requirement of prior knowledge of the faults and stationary response data, no limitation to specific structure design and is easy to implement. An application for fault diagnosis of the bolt-loosening in a satellite-like structure is taken as an example to illustrate. The results show that the proposed method is eligible of fault diagnosis for the complex structures.